Rough Idle Mazda 3 Engine Light On Code P0126 -

Is Your engine light on in your Mazda 3? A very common reason for it is the diagnostic trouble code (DTC) P0126 which is low coolant temperature. Mark shows you how to fix this problem yourself and get your car back on the road without spending hundreds of dollars.

[@yowmymen3054]

Thank you, I was able to changed the coolant temp by myself. Helps a lot! No more pending engine code.

[@carquestions]

+yowmymen Glad it worked out for you

[@yowmymen3054]

Thank you for the video post, I will try to fix my son's Mazda 3. Same problem with yours, coolant temp check engine light is on. Saves me hundred of dollars! :)

[@phillindsay1149]

extremely helpful, perfect instructions! This is how all "how to" videos should be. Thank you!

[@halofour01]

HUGELY helpful!!! Thanks for posting!

[@smrion]

Great video. I'm new to the Mazda but not car repair so I have one tip for folks with limited amount of tools, in a pinch a 3/4 inch socket will replace a 19 mm socket.

[@Neptune730]

Thank you so much for posting this. That helps me out a bunch.

[@carquestions]

Anytime Neptune - cheers!

[@harrowryan7944]

Fabulous video. Thanks Mark !!!

[@carquestions]

No problem - glad to help

[@amazydazy501]

THANKS FOR MAKING THIS VIDEO :)

[@carquestions]

+amazydazy501 No problem glad to help

[@beachwebcam]

Hey Mark - great video and great info, especially the 'gotcha' tip about the idle learn procedure. Thanks! I'm getting a P0126 too, but my engine coolant temp measurements (which I read from the ECU, using an OBD2 adapter) look normal, eg. 75C idling after a long drive (in Vancouver). I'm wondering whether I only need to replace the thermostat. Does that sound reasonable? Thanks!

[@carquestions]

After a long drive it should be between 80 and 90 so it sounds low to me - try the cheapest easiest thing first - you"ll get it

[@jordansanders1569]

*Warning*: To start off, I watched this video and it was very helpful. However, if you are going to disconnect the temperature sensor, undue your coolant reservoir cap with a boat load of rags (after it has been sitting for at least 2 hours) and make sure your engine is cold. I undid mine and damn near blew my hand off with boiling antifreeze. Thank god for mechanix gloves because I just got back from the ER and suffered some gnarly 2nd degree burns even with them on. After looking up some other videos online it is fairly common so please do not be as much of an airhead as me.

[@jordansanders1569]

BTW the part was $25 in stock at Auto Zone

[@carquestions]

Thanks for the info - very good advice - don't work on hot cooling systems -

[@carquestions]

Thanks good to know

[@hdrk59]

I thought that would have been obvious .

[@petemoss9693]

Good video - also thanks for the tip of NOT disconnecting the battery cable to change the coolant sensor - keep the videos coming .

[@carquestions]

Thank you - no problem - hope it helps

[@mudspitcufk]

***** thank God i found this video, although, you were right, my mechanic disconnected the battery when he changed the sensor and now my mazda 3's idle is going crazy? you mentioned it'll be like that for weeks, but will it turn to normal again? TIA

[@carquestions]

It might at some time if it idles long enough - hard to say for sure

[@rrmorris67]

If you watch your Temperature gauge on your dashboard it will tell you what is happening and what you need to do. If the needle is taking a lot longer to get to the middle than it used to than you know your Thermostat is stuck open. If it spikes almost immediately you know it is stuck closed but it seems to me that is super rare. If the Temp gauge is doing its thing and warming up to the middle like normal you know your thermostat is fine and you just should replace the sensor first. I had one of my Mazdas that had that code and there is also a P0128 which seems the same to me. But the gauge was moving slow so I did both. Another one of my Mazdas it only required the sensor.

[@carquestions]

Good tip Ron - thanks for the comment and Cheers!

[@hectormiguel05]

Thanks for the tip. I have a P0126 code. My gauge seems to be working fine. Will change out the sensor 1st, if it doesn't clear up I'll go ahead and proceed to changing out the thermostat.

[@neilritz2814]

Is it recommended to drain the fluid or can you do this without draining?

[@MeanManMeanio]

I have a 2007 Mazda 6 is the engine layout just about the same or close to the same? I got that code on my Mazda 6 PO126

[@DavidRappo]

Great video, thanks! I'll be doing this myself soon as all the shops near me wanted $160-250 (plus fees for diagnostics when I already gave them the error code!). One suggestion -- can you put links in the description to parts you mentioned? If not Amazon/etc links, even just the part number would help :).

[@carquestions]

+David Rappo KZbin doesn't like me adding hyper links in replies - sorry

[@frankcampos9341]

+carquestions , Hello Sir; I have a madza3 2004 my car shuts off on me while coming to a stop then turn back on, I change throttle, tune up, many more still turns off. can it be a fuel pump. idel on my car shakes little bit, I didn't want to take it to the shop

[@danielkim9997]

Thanks for this video. I have this code come up after a few hours of driving after I clear the code. My coolant level is good the the engine temps are normal. Would you recommend changing the ECT or the thermostat? Also, will anything like coolant spill out when I take off the ECT? I've seen it mentioned on other videos but not yours. Do I need to take precautions?

[@carquestions]

+Daniel Kim I mention coolant and what to do - please watch again more closely

[@lucidry]

excellent informative video - thank you for the post. I just have one question, why is the thermostat mentioned in this? Is it a 'potential issue with P0126 but not in this case'?

[@carquestions]

Yep - low coolant temp because of a faulty thermostat can give the same code

[@mtoumi9471]

thank you for this video a have the same problem.

[@carquestions]

+Messaoud Toumi No problem - tell your friends

[@reytos03]

Very helpful video, detailed and easy to follow. Thank you. Would this be the same for a 2008 ?

[@carquestions]

Maybe - give it a try it won't hurt anything to try

[@kaylanelson3591]

Hello there, Thank you for your video it was very helpful. This code came on in my 2007 Mazda 3 and i replaced the sensor first. I shut the code off. It came back on so i replaced the thermostat. Shut it off and it came back on. Would you have any idea what i should replace next or what should i do next? I really hate seeing the check engine light on. Thank you.

[@carquestions]

+Kayla Nelson What is the code that is showing up? If you don't have a scan tool just disconnect the battery BUT if you do this follow the instructions in my other video on how cure the rough running that will rsult from disconnecting the battery.

[@johnfoster9868]

Hello, great videos and very helpful. I have a Mazda 6, 2004 (manual) it loose power up in a hill or when I stop it in a hill. The mechanics can´t find the solution to that problema. How can I fix that power problema? Rgds,

[@riodaviz5787]

Thank you for this videos from you! You are a good man and very good mechanic! I got a problem with my Mazda 3, 2005...engine light is on, i start a car it works 30 sec then just stops working..after cca 30 sec i start it again and it works without stoping but i cant move the car untill is temp on 90 because it stops again and i notice that the car is not in full power when i driving it..and sometimes stops working after stoping the car while drivig it..can you help me solving the problem please?

[@carquestions]

You need to check the cars computer for fault codes and let me know what the codes are

[@timothylowe2073]

Hi I'm sorry for asking but you wouldn't know what the AT light being on from start up and staying on means do you? I know what the light represents and when you drive it changes from 1st to 2nd nicely and then a big slip into 3rd and stays there. It doesn't lose power just won't shift the 4th and 5th. Upon stopping it goes from 3rd to 1st and then the same process again. It's a 2007 Mazda 3 2.0L Maxx Automatic. It's really annoying and no one knows how to repair it. I'm trying to trouble Shoot and fix it myself because repairers here in Australia are so expensive. Thank you heaps in advance

[@jerryallright77]

Hi there, I like the videos you do for Mazda 3, Just wonder do you know where is the Mazda 3 fuel pump and the filter located? is it under the back seats? Hope you can help as I'm thinking to change it myself.

[@carquestions]

Jerry Allright Yes check under rear seat for an access panel - the filter is part of the pump it is not separate

[@CaptainMeliodas]

Quick question: If the car isn't at abnormally low temps nor overheating and the coolant is topped off, could this be the sensor?

[@carquestions]

Yes it could still be the sensor

[@travisbrunner]

Very helpful! So I got the sensor changed out but the check engine light is still on. I'm not sure what to do, should I go and get a reset done? Or will it go away with some more drive time?

[@carquestions]

Find out what code it is causing the light to come on - but wait a week or two first

[@mercury_6668]

Do you have any video how to fix dashboard lights in mazda3 year2007? Thnx

[@carfieldraymond]

Hi, Thank you for this very detailed and clear video! The same P0126 code came on to my 2006 Mazda 3 and I have changed the sensor and thermostat. The check engine light is gone! However, when I'm driving and come to a stop, the car is shaking (rough idle?). What do you think is the problem?

[@carquestions]

+Raymond Wang Watch my other video on mazda rough idle - easy no tools required - should work

[@williamaboytes4416]

@@carquestions where is this link to it? My 2005 mazda just gave this code. But it also has been rough idling whenever I’m in drive and come to a stop as well. I’ve had tune ups and replaced spark plugs but no fix. And no code. This link would help a million

[@ab2002jlisee]

Autozone recommended I replace the thermostat b/c I got this code. Should I start with the sensor first? REPLY

[@carquestions]

Try the cheapest thing first of course - but you"ll likely need both

[@neofytospapaneofytou4617]

Hi there.. First of all thanks for the video, it was very helpful.. I have a question for you.. How dangerous is to ignore this light for three days? For understanding, the engine light was turned on before an hour and i could not take the car for service the next few days..

[@carquestions]

+Neofytos Papaneofytou Generally speaking - yellow/amber lights can wait a bit - a red light cannot - the engine light is yellow

[@Ziggey32]

I have an 05 mazda3 sp23. My car jerks about like a rough gear change when trying to a accelerate in any gear even after the gear is fully engaged. this occurs constantly with the engine light off & on I'm going to get the entire cars system scanned but I've done idle relearn procedure, cleaned the maf & throttle body, checked all coils & plugs, cleaned the purge valve but no change yet

[@carquestions]

Your doing the right things - get the codes - it could be a faulty fuel pump

[@walidhanafi9418]

thanks for this video, I have the P0126 code check engine and the engine is OK but after disconnecting (replacing) the battery, my engine stops frequently when I brake, the RPM needle also fluctuate (only when engine is cold) should I go to a mechanic ? is it related to the thermostat ? thank you very much

[@carquestions]

See my other video on how to reset the idle - the computer needs to relearn it and it runs like dirt after disconnecting the battery if you don't do the relearn procedure - go to my channel carquestions you'll find it there

[@jiriskridlo9819]

Helo, thank you for your video. I have the same trouble code P0126 on my Mazda 5 2006. I was with my car in carservice and they told my only to change the thermostate. Should i change the ECT sensor too? Is it needed? Thank you for your answer.

[@carquestions]

+Jiří Skřídlo Try the thermostat first - if the light doesn't come back on then nothing else is needed - if the light does come on then change the other sensor

[@abdelkrimrezki7999]

Hi I have a Mazda 3 2010 and I have many problems with my rpm when I don't accelerat the rpm falls to 800 ?

[@romemercado9001]

hi there, thanks for all your effort to help people. every time i experience check engine light i just disconnect the battery and will work for only a few days and will get back again. do you think, i also have problem on my coolant?thansk and more power to you!

[@carquestions]

Hard to say - you need to get the diagnostic trouble code from the car and tell me what it says - there may be multiple codes

[@jonathankoehn7186]

So ya one of my customers has a 2006 Mazda three with that code. It not blowing hot air thru the hvac. So after changing thermostat due to orignal part and lots of milaege on the vehicle it still was not blowing very hot. It would after revving the engine slightly. So I went in and changed the water pump. The replacement water pump had a much bigger impeller. So much larger in fact that I had to raise the engine up for clearence. I'm not very familiar with these as vehicle. But back in the day (early 2000s) the VW Passets and Jettas had water pump impeller problems.

[@carquestions]

Sounds like you got it pinned down - good work

[@dh4976]

Mark would it be acceptable to only replace the coolant temperature sensor? If the check engine light doesn't go away I would resort to replacing the thermostat as well, but would like to avoid that if possible. Thoughts? Thank you

[@carquestions]

+D H Sure good idea - but drive the car for 50 kms or so and if the light does come back then change the T stat

[@rogercosta2266]

My 2005 mazda has code p0300. Already performed the disconnect battery and plug it back and let it idle to relearn the idle I've done it a couple times still runs like crap. This was all due to an alternator that wasn't charging now I got this on my hands. Replaced maf sensor ,spark plugs cleaned the throttle body checked for air leaks. I've basically come to the end except clean injectors and what else not. Any thoughts would be appreciated. Thanks nice vida.

[@carquestions]

Keep at it Roger - go over your work again and make sure there is no mistakes - ie like the throttle body boot fits right and there are no cracked vacuum lines or leaks - Re do the idle learn - increase wait time - keep at it and you'll get it right

[@richardoseidarko7385]

Hi there, thank you for the rough idle video. I have the 2007 mazda 3 and after having a battery change the engine light is on. I have tried the rough idle trick but yet anytime I stop in traffic, the engine goes off and I have to start it again but not all the time. What could the issue be. Please help me out. Thanks

[@carquestions]

check fuel pump pressure I suspect failed fuel pump

[@joshgarcia1238]

have a 05 Mazda has a misfire..comes and goes any ideas ?? changed sparkplugs,injustors,coils still have issue

[@carquestions]

Josh - What codes are coming up?

[@JamminWithJake]

I have the 2006 version of this car- same engine code. However checking PIDs, ECT goes up to operating temperature; A TSB associated with this code indicated that the code is set when ECT hovers around 160 degrees, but as i stated, I am getting about 200 degree range. I'm thinking the ECT sensor may be faulty, because to me, it seems as though the thermostat is working. (blows hot air) Any thoughts?

[@carquestions]

I think you nailed it Jordayn - the good news is that youu are not spending hundreds - given its age change it out is my advice - Cheers!

[@neilmarciano6430]

My friends Mazda has CEL codes P0126 and U0155 (lost communication to instrument cluster). The only thing on his instrument cluster that doesn't work is his temperature gauge. If we replace the thermostat and the sensor, would that fix the U0155 or are those two totally different issues?

[@carquestions]

Totally seperate problems completely - unless the windshield was replaced and is leaking water all behind the dash or something stupid like that

[@jennifera.sommers9146]

you seem really good with the Mazda 3 the temperature light come on at start but maybe within two to three minutes it goes off and also I have a high idle can you let me know what's going on and what to do.

[@carquestions]

+Jennifer Sommers You need to get the car's computer checked for fault codes first. You can buy a scan tool and check it yourself or get a mechanic to do it. Once that is done you'll know what needs fixing

[@Italianborn]

Hi nice video, i got a mazda 6 with code p0126 but would the thermostat make noise when raving the car ? Cause as soon as I'm raving it, makes a noise coming from the belt and when i accelerate above 70-80km/h the noise is incredibly loud, any suggestion or help ?

[@carquestions]

Could be anything being turned by the belt - could be a bad water pump impeller - bad idler bearing, alternator, etc - run it without the belt on for a minute to confirm and check each pulley / bearing by hand

[@Italianborn]

carquestions thanks to answer me right way hopefully wont cost me my right arm !

[@carquestions]

Turn each pulley and check if bearings are bad or noisy - spin as fast as you can

[@pizzaaddict5000]

2007 Mazda 3. In my case changing the thermostat solved it. I did not have to change the sensor. The only time the P0126 code was being triggered on my car was when the ambient air was under about 45F/7C. On warmer days it didn't throw the code. It seems the code is triggered if the coolant temperature stays under 180F/85C for a prolonged period. On warmer days it had no problem reaching 180F/85C, so no code. I didn't really have (or couldn't notice) any side effects from this issue (other than the check engine light). After changing the thermostat there has been no more check engine light.

[@carquestions]

+pizzaaddict5000 Excellent result - happy motoring

[@Haseeebo]

push it over 150km/h and see what happens

[@carquestions]

+Haseeb Syed Don't bother - waste of time

[@Haseeebo]

The engine light comes back, thats what happens. lol

[@jaykalyan8911]

First time we scanned it gave B1261-(sun load sensor short circuit to ground) we have changed the plugs, air flow meter and cleaned throttle body also, had it checked for Transmission, they confirm it is not transmission problem. They say it has something to do with engine as there may be air licking some where

[@carquestions]

fuel pressure regulator maybe failing and yes a vacuum leak is possible

[@Angel-xv1lx]

Is draining the coolant required before replacing the ECT sensor? What about the thermostat?

[@carquestions]

yes a good idea to drain and change both

[@carquestions]

good idea to do it

[@zb2584]

@@carquestions I have a 2007 Mazda 3... Today my engine light came on, I took it in the shop and ran the diagnostic report... This popped up: PCM-P0126-FF Stable ECT(Engine coolant temp)not obtained... Should I do both the sensor & thermostat? Also should I drain all the coolant before replacing them both? What is the easiest way to drain the fluids before installing the parts? thank you for all the help, awesome video 👍

[@nsahar4214]

hi there, i am running into a little problem just wondering if you could help. I swapped mazda3 2006 2.3L engine with mazda5 2.3L that came with its wiring and all that however when i start it turns over but doesnt start. Would really appreciate if you know on what else do i need to do to get this working. Thank you kindly

[@ryanb2369]

Have spark and fuel pressure?

[@ojav4254]

For such a popular car, they sure made it really annoying to replace parts or fix. Even something as simple as replacing a headlight bulb turns into a nightmare because of those dumb metal clips. P.S I have the same issue as in the video and mechanic asking for around $400 CAD. I myself have no experience with my mazda other than light bulb and battery replacement. Is it worth it to just take the car to the mechanic? How harmful is it to the car to ignore this error?

[@carquestions]

You shouldn't ignore anything plus it might not pass an emissions test - shop around for mechanics and tell them to replace just that part - the price should come down

[@neilpirelli9240]

the clips are easy when you do them properly, find a good picture of one and it will make sense, it doesnt take much pressure at all

[@samanqurbany3009]

Thank you for this video my mazda 3 2017 hard shaking only in the morning when the engine is cold, after 1 minute everything become good. can you help me?

[@carquestions]

Check owners manual to see if spark plugs need changing Saman - also check computer for codes and let me know what you find - Cheers from Canada!

[@samanqurbany3009]

carquestions Thank you for ur reply❤️ I changed plugs only 2 weeks before. computer checking showed only exhaust and Ignition coil (number 3) we substituted Ignition 1 with 3 and restarted, after one day later showed the engine sign again also computer check show Ignition coil number 3 again.

[@carquestions]

@@samanqurbany3009 You'd better do a leak down test and compression check on all cylinders - you may have a bad valve

[@jaykalyan8911]

Mate--Mazda Axela 2008 --what could be the problem if the car is driven at constant speed (50kmph) it starts to surge when travelling under load (going up hill)

[@carquestions]

Get engine codes first thing - might be plugs etc but you need the codes

[@mikeortega363]

i have an 06 mazda 6. ik this is a vid for mazda 3 but i need help. Idle goes up and down. while driving it jerks and hesitates. no check engine and no codes. bad mpg and just a nightmare. please i need help

[@carquestions]

Try my video about relearning the idle kzbin.info/www/bejne/baKVZaWIaZVkiKM

[@MrMisterChiliPepper88]

Subscribed

[@curtisperson8239]

Question, my car is full of "free on" the fan does blow but not cold. Help.

[@carquestions]

You need to check to see if the compressor is turning - let me know if it is

[@maxlahoud]

I have a 2004 Mazda 3 with this code that just came on. Replacing the sensor and thermostat should alleviate the code?

[@carquestions]

+Max Lahoud There is a good chance it might fix it - lots of others have done it with good results

[@maxlahoud]

+carquestions knocked it out yesterday in about an hour and it's running smooth as ever. Thanks!

[@dynobot7]

my Mazda 3 (2007) only has 60,000 miles on it. Should there be any issues with it with somewhat low miles? It was in an accident and the radiator was removed and re-istalled so i'm not sure if it was the repair process or just a faulty sensor? The check engine light is on and the code is P0126.

[@carquestions]

+dynobot7 I'd try the replacing the thermostat first - I know it has low miles but some parts fail with age and the thermostat is one of them

[@dynobot7]

Thanks! Got the thermostat changed out so the I'm all set.

[@cholemcnasty9517]

I have a Mazda 06 hatchback and I was driving n just shut off ccrankd over but doesn't want to start at "AT" light comes on. ?

[@carquestions]

You have a transmission problem - check and top up fluid and get it in to a shop ASAP

[@reynaldoranjo1997]

carquestions hi sir good evening i have problem in my car mazda 3 2007 model.very rough starting and when i long travel suddenly mar car not accelerate need to rest for 30min to continue driving.hoping u can help me thank u

[@carquestions]

You need to get the codes out the car's computer and start your diagnosis from there

[@im1dermike]

In the beginning of the video, you say you need 2 things - an ECT sensor and a thermostat - but then you only replace the ECT sensor. What about the thermostat?

[@carquestions]

+im1dermike I wanted to limit the work and expense so I just changed one thing at a time to see if the problem went away - luckily I on this car I chose the right one - if it didn't work I would have ended up changing both - just a money saving tip

[@im1dermike]

+carquestions Thanks for your reply (and video!). After doing more research, it seems like a lot of people are saying that the P0126 code on the Mazda 3 corresponds to a bad thermostat 99% of the time. Is there any way to determine which I should try to replace first? Or would it not be a bad idea to replace them both at the same time on a 2005? Thanks again.

[@carquestions]

+im1dermike Best idea is to change both since the thermostat wears out at some point anyway -

[@im1dermike]

+carquestions Thanks! Lastly, how severe is this issue? Would it be a problem if I waited a week to fix it and drive somewhat minimally until then?

[@carquestions]

+im1dermike Should be able to wait a bit longer

[@sergiotomita6462]

Can the sensor fail with out sending out a code? My Mazda 3 2010 is over heating but I don’t get anything on the dash board. Also it won’t tell me wen I am low on antifreeze. Any ideas?

[@carquestions]

It could if it had a bad head gasket

[@TheKrayze]

question, I have a Mazda5 with a same code. P0126. My car heats and cools properly, so I think the thermostat is good. Would you agree?. I plan to replace the temp sensor tomorrow. I think that is the issue. The question I have is will the check ermine light go away on its own if/when the sensor is replaced? (given that the sensor is the issue) to get my wire harness off, the plug did turn which also leads me to believe its the sensor and not the thermostat. If the light does go away, is it immediate or after a certain amount of driven miles? Thanks

[@carquestions]

The light should go out on its own right away - if not disconnect the battery and watch my other video on idle relearn since it will run rough after disconnecting the battery - if it still comes on change the thermostat - how the engine feels warming up is different to how you experience it warming up -

[@TheKrayze]

***** thank you for the quick reply. I was thinking of getting the thermostat out while in had the coolant flushed. Do you know of other symptoms that would point to a thermostat? I am experiencing the idle issues. Primarily when I am driving and come to a stop. It almost stalled today. I disconnected the battery 2 weeks ago and the computer did not reset in time for an inspection. The emissions failed because it was not ready. I had driven 100 miles over the course of a week, but all city driving under 15min/10 miles. I drove for 45min highway, about 30 miles. The light came back on, so I take it the computer reset.

[@carquestions]

TheKrayze Have you watched the other video about the computer relearning the idle? and have you tried it? - the thermostat should fix it if the sensor hasn't

[@TheKrayze]

***** no, I had not watched the video yet. I will do so.I only asked about other thermostat symptoms to see if I could rule out the thermostat. Again, thank you for the replies. You video was informative. All will be revealed tomorrow. 😃

[@ksafan838]

I have a 2007 Mazda 3 and the engine stumbles at idle when the ac is on. Any idea what could be causing this? Thanks

[@carquestions]

Get the trouble codes if there are any - then start troubleshooting

[@julios.5411]

I have a question, before take out de sensor, I need drain the coolant from tha radiator?

[@carquestions]

+Julio Silva Yes you do - at least half of the coolant

[@julios.5411]

***** thank u

[@ahmedi5102]

what do you think can burn up the ecu on mazda 3?

[@carquestions]

A bad mechanic can - most of the time the ECM is fine and the mechanic is wrong

[@yilancio]

I believe this is the same engine used in a 2005/2006 Ford Focus. Can anyone confirm? (I read P0126 on the daughter's 2006 Ford Focus, but the CEL has since shutoff.)

[@carquestions]

Thanks for the info ASD

[@rufimn]

Hello Sir, My car (Mazda 3 2004) has p0128(coolant thermostat) code. Upon some investigation, i noticed that my thermostat comes up to the mid level after 5 mins of driving(i.e stays at 50% after 5 mins of driving), which i think is normal so do you think coolant thermostat could NOT be the issue in this case. I was thinking coolant sensor might be the issue, so please let me know what should i do in this case. Thanks,

[@carquestions]

I'd change the thermostat first then try it - if you still get the code then change the sensor - let me know how you make out - cheers!

[@rufimn]

Thankyou for letting me know Sir. The thing is i'll have to pay for thermostat and/or sensor plus labour($$$) to actually see whats the problem , since i guess i can't do it on my own :( ?? How about if i leave the codes P0128(Coolant thermostat - considering that the thermostat do reach at 50% and the sensor might be the issue) as well as P0455(Evaporative System leak - Large leak detected)?? I guess i won't have any issues with engine in the long run, right??

[@javier4781]

Did this cause you engine revs to go up and down on idle?

[@carquestions]

Yes it did Javi

[@bolan236]

maybe you could post the parts link in the descripetion so but directly, thank you

[@carquestions]

I would if everyone from around the world lived in the same city - also I don't advertise for anyone

[@bolan236]

i think its ok, just a amazon link or ebay link

[@mb1636]

carquestions .i think you can get a commission on amazon if u established an account ..not so sure the setup but i saw one youtube channel does it. Thnx 4 video.

[@joshgarcia1238]

Yeah I swapped all coils and replaced all sparkplugs.. I'll try the sensor

[@carquestions]

Keep at it Josh you'll get it

[@carlossantiago9108]

hey! i have a 2005 mazda 3 2.3. the car runs fine when i start it in the morning.but when it warms up it wanna buck and stall. when it stall and i try to turn it on it don't wanna start i habe to let it cool down

[@carquestions]

What are the trouble codes from the computer?

[@11masterjay]

Sir my mazda3 2006 2.0 has a good idling but when u hit the acceleration thats the time it become rough and sometimes it shuts off can u help me with that sir

[@schmoab]

I have the same problem on my Miata with the 2.0 engine. See his video on the idle learn procedure.

[@kiratouimoussa6602]

I didn't catch what to do after disconnecting-reconnecting the battery between 3:46 and 4:00 . Please help !

[@carquestions]

You don't need to disconnect the battery but if you did you better check out and follow the instructions on my other video about mazda rough idle

[@kiratouimoussa6602]

Thanks man, it worked 100%. My Idle is steady now :) My OBD shows an irregular temperature for the coolant ( 85°C, then minus 30°C when I drive). I will change the sensor as shown in this video. No need to change the thermostat.

[@lotus956]

Is there another ECT sensor on passenger top side of radiator?

[@carquestions]

it varies by model and year so maybe

[@teezz3722]

I changed the sensor but I still got the code a few days later could it just be a faulty part?

[@carquestions]

Could be but also wiring needs to be checked

[@whatxupxbra]

@carquestions I had error codes P0126 and P0128. I changed both the thermostat and ECT Sensor. P0126 went away but a couple days later p0128 came back. Any suggestions?

[@carquestions]

Cross Innovations Some things not right - either the thermostat you put in is faulty or the sensor is - The car has to warm up at a certain rate - check with a digital heat gun - it also has to fully warm up and at a certain rate or the computer will set a code based on what the sensor is telling it but time is involved also

[@whatxupxbra]

***** thanks for getting back to me. from what I understand P0126 refers to the thermostat while P0128 refers to the sensor? Seeing that I'm getting P0128 again I'm guessing the sensor is faulty. Where would I be checking with the heat gun and what temperature am I looking for after how long? And would this test determine that the thermostat is faulty or the sensor?

[@carquestions]

Cross Innovations Point the temp gun at the thermostat housing - temp should read 176-183 or higher within 20 minutes - if lower reading is lower then change the thermostat not the sensor

[@whatxupxbra]

***** ended up taking it to my mechanic who says the computer needs to be reset in order for these new parts to operate correctly

[@whatxupxbra]

***** had monitors reset at mazda dealer. 45 miles later the light came back on. temp at thermo housing is reading 170 at 10 minutes of idol. any other suggestions?

[@christaiwo5515]

My check light comes and go, could it be the coolant too? Also I have this AT light coming up on my dashboard. What advise can you give me on it? Its a 2007 Mazda 3.

[@carquestions]

The AT light means there is a problem with your Automatic Transmission - check the fluid level immediately AND get it to a transmission place ASAP

[@christaiwo5515]

Thanks for the reply, I changed the fluid just last week and the light still comes up maybe once in a day or two. Do you think its the TMC or the transmission itself? Am confused !

[@carquestions]

Chris Taiwo You can disconnect the battery for 6 minutes then follow the video for the idle relearn procedure - if that doesn't fix it the light is definitely indicating an internal transmission problem of some kind - get it checked out - transmission are big $$$ to fix - the sooner the better

[@christaiwo5515]

***** thank you so much for the advise. I took it to my dealer and the run a scan on it. The scan found the code U0101 (unable to communicate with transmission) the guy said its either an electrical problem or the TCM. What do you think thou?

[@carquestions]

Chris Taiwo I think this is a common problem and they know all about it - it will likely need the TCM replaced - $600 or more - try asking for warranty on it

[@bobtim1008]

Do I need a specific etc sensor or can any work

[@carquestions]

You need one for that make model and year of course

[@IphoneMaster19]

I do have this code on my mazda 3 but im wondering if i can still drive whitout changing anything?

[@carquestions]

Jérôme Joyal I can't recommend driving a car with a problem but will say many people have driven with this code for years without knowing. Know what I'm saying?

[@IphoneMaster19]

Ok thanks !

[@fernandovergara3157]

hi , my mazda 2004 check engine goes on and off. I had it diagnosed and error code P2177 was found. what shall I do to correct it?

[@carquestions]

+Fernando Vergara I'd suggest replacing the 02 sensors even if they test ok with a scan

[@aldosandoval6587]

Fernando Vargas did you fix it? I got the same problem.

[@joshgarcia1238]

misfire codes for 1 4 only. I did that reprogram the one I saw you posted worked for awhile the it started to misfire again same codes for 1 4 cylinders

[@carquestions]

Do me a favour and swap the ignition coils around to see if the missfire problem follows the coils - if it does - new coils are needed

[@crzivan01]

Is this the 2.3 or the 2.0? What year?

[@carquestions]

It should say in the video

[@rogercosta2266]

The thing thing is also when I unplug the maf sensor the car idles just fine without sputtering or idling funny. I already tested 2 other maf sensors and no luck. One of the wires was cracked and checked the rest and repaired it but no luck. I'll keep at it but this one's really cracking my skull.

[@carquestions]

Keep at it you'll get it. If one wire is cracked chances are more hiding out of sight. Also it sounds if there is a vacuum leak somewhere.

[@sgar3141]

Anyone have a problem with Mazda 3 08 with p0037 with the oxygen sensor downstem bank 1 sensor 2

[@alextm420]

Do you need to drain the coolant before changing the sensor?

[@carquestions]

Alex - you do need to drain it or be prepared to catch what comes out - your choice my friend

[@alextm420]

Thanks for the advice and the quick reply!

[@OMOG211]

i noticed that my mazda 3 was running out of coolant last night. I parked at store and after 30 min ready to leave the car it won't start. I putted coolant on it and works again but radiator fans keeps ruining all time since then…

[@carquestions]

+Edgar N check for codes on computer

[@manuelnunez7991]

mazda 3 2005 2.3 sometime when i shift to d or r the car kicks and you can see the at light ,car don t go to 4th gear .

[@carquestions]

Get the transmission checked out Manuel

[@javier4781]

Transmission Control Module. Its located under the battery. Theres a person on eBay that fixes it. I cant remember how much i paid, but it was over $100 for sure. You can buy find one at a junkyard, or buy a used one, or get it repaired.

[@manuelnunez7991]

Javi Habi thank you for your answers but already check the transmission and it is ok and this model 2005 don t have the tcm module down the battery already check this two opcions and i have the same issue where is located the tcm or there is not tcm in 2005 model ? the guy ho se the car says that we have to change the computer what do you think about that.

[@javier4781]

That's what im saying it is, its the transmisson control module (TCM) its the computer to shift it. Its above the transmission, underneath the battery box. www.ebay.com/itm/Repair-Service-4-2006-2009-Mazda-3-Transmission-Control-Module-Mazda3-TCM-TCU-/252160180090?fits=Make%3AMazda%7CModel%3A3&hash=item3ab5eaff7a:g:1nsAAOSw5VFWPQlG&vxp=mtr

[@AadarshBohara]

How critical is this? Is this a must fix issue?

[@carquestions]

If you're not having this issue then no. If you do have the code and nothing else you can still drive the car. Must fix? you decide

[@whatxupxbra]

***** do you have a video for replacing the Thermostat?

[@carquestions]

Sorry no -

[@brightchili4266]

what happens when mazda 6 2006 engine stops running while driving?

[@carquestions]

Engines will stop for three common reasons in this order - electrical problems, fuel problems, mecahnical problems - See if the car has any trouble codes and of course has a tank of fuel - then get back to me

[@mx.j262]

I am experiencing some jerks when driving my mazda 3 2015 1.6, it has 58000 kilometers on it, i started noticing this one week ago before that the car was smooth. It does happen at lower speed when i am on highway at higher speed.like 100-120 kmph it does not happen but when i start and accelerating it happens once in a while and is noticable.

[@carquestions]

Check for codes - but do the procedure first

[@mx.j262]

@@carquestions which procedure ?

[@mx.j262]

@@carquestions jerking issue may be because of fuel filter , spark plugs or some misfiring i have ordered a bluetooth type OBD device i will connect it to the port in the car and then see information on my android phone by connecting to that OBD2 scaner

[@carquestions]

Sorry I wasn't paying full attention - I have another Mazda video about disconnecting the battery and resetting the idle quality to get the engine to run smooth - the procedure in that video is what I was referring to

[@mx.j262]

@@carquestions yes i know that video i have seen that .. Okay i will do that .

[@covfefeo_o8724]

Guys I need help.. I have mazda 3 2005 1.6... When ever I on ac my car accelerater go up n down automatically.. Then I turn off Ac car is normal again.... It's only happen when I on Ac... Can anyone tell me what is problem?? Please

[@carquestions]

Get your AC system checked out - might be causing this problem

[@hondafreak8613]

wouldnt you assume the sensor is good, if its telling you the car engine has insufficient coolant temp. i would think the sensor is doing its job correctly. would think if the sensor is bad, it would throw a code for malfunction. i would replace the thermostat. that is what causes the over cooling. the thermostat gets stuck open and never closes to get the engine up to temp. just because the gauge shows temp halfway dont mean engine is up to temp. the engine could be at 130 degrees and show the temp gauge is in the normal range. buy the thermostat/housing its $23 at parts store

[@carquestions]

certainly good advice

[@arvindaranciang6709]

whats the problem if your dashboard lights in mazda3 is on and off?

[@carquestions]

Arvin Daranciang When the light comes on while driving there is a problem the computer has detected. If it goes on and off its an intermittent problem but still a problem -only way to know exactly what it is is to have a scan tool hooked up to it to retrieve the codes

[@ericvenzon9626]

+carquestions hi, I guess my mazda3 is consuming more gas what should I do? Thanks.

[@carquestions]

+Eric Venzon Check for leaks, do a tune up and thats about it

[@ericvenzon9626]

+carquestions I have P0126 issue with my mazda3 and got rid of it with a scanner, does the ECT affect increase gas consumption? Thanks!

[@carquestions]

+Eric Venzon Deleting it with a scanner won't solve your problem - the light will just come back on and yes ECT could increase fuel consumption if faulty

[@Godspitney]

Are you aware of a U0121 code ?

[@carquestions]

ya- you have a communications system fault - lost communication with ABS computer

[@locfan407]

Hi, where did the thermostat come in?

[@carquestions]

You might want to change the thermostat at the same time - but most cases I'd change the sensor on this car first as long as the temp gauge was reading normal when warm - its located midway down on the engine front right of the car - just follow the hose.

[@mitchlillard3887]

***** I did disconnect the battery to "reset" the code and what you described is exactly what happened to me LOL... I am having that code but it seems like my car is not warming up very quickly especially when its below 30 degrees outside. I am thinking I need to replace the thermostat, what do you think?

[@carquestions]

Mitch Lillard Yep - change the thermostat

[@clivedaimon8888]

@@carquestions hie

[@curtisperson8239]

Sorry, I've got a Mazda 2007 3i

[@kaylanelson3591]

p0126