How to test and fix a PGM-FI main relay - Honda/Acura

Honda PGM-FI Main Relay Testing (1998 Honda Prelude)
How to test and fix a main relay on a Honda or Acura.
Engine Performance Diagnostics chapter 18
Symptoms (typical of a main relay issue)
intermittent no start
start/stall
stalls and will not restart for a period of time
Fix
replaced PGM-Fi main relay fuse
Tests shown
how to determine what is powered by the main relay
main relay wiring diagram review
how to identify condition of the main relay by testing for power at the fuel injectors and idle speed control motor
how to test a PGM-FI main relay
how to locate the main relay
how to remove the main relay
how to locate a cracked solder joint on a circuit board
Tools used
incandescent test light
soldering gun
Playlist
(Chapters 17, 18 and 19) Fuel Injector Testing
• (Chapters 17, 18 and 1...
Related videos
Operation and testing of a Honda main relay (PGM-FI) - an SD Premium video
• Operation and testing ...
How to identify a bad main relay on a Honda (PGM-FI)
• How to identify a bad ...
How to test fuel pressure, injector pulse and spark with basic tools
• How to test fuel press...
For more information on this topic, I have written a “field manual” called Engine Performance Diagnostics which is available at www.scannerdanner.com as an eBook or paper book.
Want even more diagnostic training? Whether you are a DIY trying to fix your own car, someone looking to become an auto technician, or a current auto technician that wants to get more into diagnostics, subscribe to ScannerDanner Premium www.scannerdan... There is a 14 day free trial.
On ScannerDanner Premium I will bring you right into my classroom at Rosedale Technical College. You will find page for page lectures taken right from my book as well as exclusive classroom type case studies. What is so special about these classroom case studies? I pull live problem vehicles directly into my classroom and we troubleshoot them in real time, using and applying the theory and testing procedures we learn during the classroom lectures. There is no better on-line training of how to troubleshoot automotive electrical and electronics systems anywhere!
Disclaimer:
Due to factors beyond the control of ScannerDanner LLC, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. ScannerDanner LLC assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. ScannerDanner LLC recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of ScannerDanner LLC, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not ScannerDanner LLC.

[@martythepainter]

I seldom comment on videos but wanted to say VERY WELL DONE! Bright video, loud and Clear audio, and no bullshit nobody has time for. Your the man.

[@ScannerDanner]

+Marty Merryfield thanks Marty

[@pickumtee6882]

@@ScannerDanner hey hopefully all is good… I’m here struggling with an o2 sensor issue…. (Think it’s in the harness)I watch ur videos tried the harness signal wire connector with test light to negative get no light (scanner says before touching wires 3.803 n o2 unplugged )when I touch it with test light goes to 0 What Does that mean? Please help n god bless

[@ScannerDanner]

@@pickumtee6882 you shouldn't get a light on the signal wire, ever. What are you working on?

[@esroberto1]

THANK YOU for the only USEFUL video on main relays on all of youtube. No one else bothered to show us exactly where the thing is mounted under the dash, they all assume we take cars apart for a living like they do -- useless! Can't thank you enough for this.

[@kneedown4GOD]

this was a reminder to look for the simple things first.just like today one of my techs couldnt get an a.c. compressor to run,after looking for almost an hour he came and got me,i checked schematic told him to check fuse 16 and he said he already checked all the fuses.i suggested a recheck and sure enough a blown fuse from the previous compressor,s bad clutch.loved this vid as always brother,GOD bless!

[@doubledeeeeeeez]

Just fixed buddies 98 Honda Accord reflowing solder on bad board thanks to this video. Kudos to uploader. Wiggle check wires with key in 2 click position to verify you have cracked joints. you will hear relay click and green key light will show.

[@tommydeese5128]

Thanks Man, I thought I was going to have to change the the fuel pump until I saw your video,found circles on two of them soldered and fixed it but bought a new relay anyway.Great Video !!! Thanks

[@happy543210]

I love that chirp that the 90's Hondas made when they start up. I used to own a 96 Prelude. It's still running after 300K miles.

[@thedronezone4924]

Hi , I've been searching for days to find the no-go-problem on my Honda Civic 2.0 i TD from 1998 with a ratteling main relay... finally, after checking the complete wiring, I found this video. In a matter of minutes it is fixed ! Thank you thousand times, Best regards, Rudi (Belgium)

[@ScannerDanner]

Awesome! Thank you

[@patagualianmostly7437]

Spot on Video & advice there, ScannerDanner. Had an Accord fail to start right outside my door. Turned out the car was always parked in the shade at home but was outside in full sun that day for several hours......Just refused to start. Took out that board & there they were...little rings around those big terminals: Re-soldered them plus a couple that looked a bit dodgy.....Fired up straight away.....That was a month ago.....no more problems reported....despite the outside temps increasing on a daily basis. (Southern hemisphere.)

[@Avicron]

Thanks for taking time to put your great informative videos out . I was able to fix my main relay on my 91 civic and get running again . Cheers mate !

[@iraysirs5269]

This is helpful information for my SE coupe 2002. Now I'm in the process of fixing that problem on my 1990 accord. Thank a million times.

[@ScannerDanner]

I totally just saw that! That confirms a loose fuse doesn't it. I will have to let this student know that he needs to tighten up the fuse terminals for sure. Great catch guys!

[@ScannerDanner]

no problem at all my friend. glad to help

[@carpediem939]

Thanks you so much again for the valuable information that I know most people would've charged me for, and also for your time. I'll have to do a good deed to compensate now. Cheers!

[@mdvalenz1]

Thank you for the walk through. My wife's car is starting again.

[@RAFICKDAMISONMOYO]

I don't know Paul how to thank you for the information, Knowledge, Skills and Experience I'm gaining from you through your KZbin channel. You really Know things. You Are Greater Person I'm my life as Auto Electrician. Thanks Forever Paul Danner ❤❤❤❤❤

[@ScannerDanner]

I appreciate that!

[@technodance_me]

Thanks. This really helped out a bunch. I checked my fuse but didn't realize this relay was the issue. Popped it out soldered it and Bob's your uncle.

[@ScannerDanner]

awesome!

[@COSHAM77]

Thanks for that just fixed my sons 89 crx i never would have found the problem turned the key and it roared into life starts quicker now to. Thanks mate

[@mattsedlacek9068]

I had this problem on my 2003 Honda Pilot and it finally died completely on the freeway where I coasted to an exit safely. An hour of it cooling down and about 20 cranks and lots of taping the module with my knuckles didn't help start it. Had it towed home. Two days later, I tried starting it and it started right up. It had been doing this on and off for about nine months and just got worse and worse over time. What I learned was that my 25W soldering iron wasn't enough heat for the joint and the large relay pins, etc. I switched to a adjustable soldering station and at 700 degrees F it still wasn't enough heat. I finally cranked it up to 850 degrees F and it was able to do a good job. I first used solder wick to remove all the old solder and cleaned up the joint real well. I then used a rosin-core solder and got real nice new solder connections. The car started right up and has worked fine (so far) for about seven restarts, even when the engine was hot and then sat for about 10 minutes (a typical stop at a store, run-in, and back out). Really appreciate your videos. Thank you.

[@typhoon320i]

Thanks for the in depth look! Both my Accords have suffered from a bad relay.

[@ScannerDanner]

It didn't blow, it was an arch from poor contact, at least that's what I think it was. I didn't even realize that happened until you guys pointed it out. The fuse never blew so it has to be from that. Also that matches why a simple bump with the foot could pop the fuse out. It was loose to begin with.

[@toreal8838]

Thank you so much for posting this video... Helped me fix 99 Ac. Rl.... Blessing to me and my family...Thanks Again...Lj.

[@ScannerDanner]

sweet! Thanks for the comment. I'm blessed in return

[@joserotary9636]

Just had that problem with my 1992 eg si hatch, bought a new one but I will do this to the old one just to practice, thanks 💯👍👍👍

[@treblarefils]

Nice to see the theory behind this stuff

[@ScannerDanner]

I agree that this shouldn't have happened if the fuse was holding better. I think it was loose to begin with and maybe not in all the way? Probably would have been a good idea to try and tighten up the fuse terminals in the box. I don't know if the kids foot slipped off the clutch or what happened. All I know is they were attempting to pull it on the alignment rack.

[@ScannerDanner]

my guess is the 200+ volts you saw is a milli-volt number. So you are missing power to the solenoid. Ignition switch, park/neutral switch problems possibly. You need a good wiring diagram. There may be a relay and anti-theft system involved. too.

[@ScannerDanner]

ahh, I would look there first. a custom alarm system will usually cut the main ignition crank wire just below the steering column and run it into a relay (aftermarket and part of alarm system add on). Find this wire and remove both ends from the relay and re-attach them.

[@erroldillon1548]

This is the best video on the main relay I've ever seen. You know your stuff!!! This is fantastic!!! On a scale from 0 to 10, this video is a 1000!!!! Best video on youtube. I've seen so many people try to explain how to check for the main relay. This is technically how to do it the right way.

[@Liberatus]

Thank you very much for all “your” hard learnt knowledge shared freely on utube, finding the wiring diagrams must be hard?

[@ScannerDanner]

If you can use a multimeter and follow directions, I can walk you through it. Just be patient with my response time. Start by removing the "Starter Cut Relay" in the underdash fuse relay box (left side of dash). In the crank position you should show 12v on two of the pins in the box. The result of this test will give us good direction.

[@brandonmartin2432]

ScannerDanner Having trouble bro can you help me

[@ScannerDanner]

I know, right? The story was the student was pulling it up on the alignment rack and it shut down. When I asked the kid he said the problem was intermittent and had done this before. Obviously a separate problem. I guess the lesson here is to question the customer better. The question I asked him in the video, I should have asked earlier on. ("is this the first time this was a no-start?") It's funny, earlier in the video you can see the fuse laying there. I didn't even notice it.

[@carpediem939]

2/2 By the way, I know a little about multimeters because I fixed a laptop's bad charger using it before, and I should've seen that milli-volt reading guess. I'm off to buy a cheap test light (which will come in handy in the future anyways) and read up more on that ignition switch tests, but understanding that wiring diagram sounds scary, but I'll try my best. Thank you again!

[@djdranchak]

I just resoldered the points on my Fuel Pump (PGM-Main) Relay circuit board on my 1995 Acura Legend on your recommendation and it actually worked! Thanks so much for the video.

[@thebestofall007]

I just played it safe and reflowed ALL of the joints on my CRX's main relay. That solved my issue w/ the no starts.

[@SharkNewGeneration]

Great Explained 👍 thanks

[@jacksonpuckett6115]

Nice vid ScannerDanner. I just checked my Mistuba main relay in my 98 crv and don't see any hairline cracks. I just bought this car and having an intermittent crank but no start issue. I just spent about a grand in parts and had the head reworked, (burned exh. Valve) and replaced all ignition components while there. New dist., wires, plugs. I have yet to adjust the timing on it but probably will tomorrow. Runs great when running. I haven't had the car but a week so I'm not sure how intermittent the problem is. When it does start it sounds like its barely firing, or catching, like holding the starter engaged longer helps it get to firing somehow, if that makes sense. But once running it sounds great.

[@dataquester]

good explanation bro!!! i had this same prob on a 98 accord....

[@ScannerDanner]

Thank you so much. Keep watching, I have 180 other videos too:)

[@mixedboi]

Hey Paul I've got an intermitent problem on my civic mb, is when I start it in the morning, it would be like the engine cranks 3 times and it fires up, after a drive, when the engine is hot, sometimes, it takes 10 - 11 engine turns before firing up. Now I know internet diagnostics are crap, but what would you say Paul? Fuel system lack of priming, or main relay complaining? Its ok when I cycle the key twice, no matter what though.

[@FroztiProductions]

Starts fine in the morning but the longer I drive the less hp I seem to have. After I drive it long enough it slow cranks if I try to turn it back on but I can always get it back on. Longer I drive, slower it cranks. Could this be main relay? 97 civic ex

[@ScannerDanner]

you were right, nice catch. read my comment about it above

[@921vrock]

I did it Holy shit It worked I couldn't have done it without you

[@Stribman]

excellent video just want to add a little, I had this problem several times replace relay repair relay comes back , when fuel pumps get old or fail they pull more juice cause more heat consider replacing pump if repeats,

[@ScannerDanner]

Great advice, thanks for the tip for the community!

[@TheMasterMechanic01]

Very good video helped me with my car I appreciate it

[@glasser2819]

it's even simpler to just: LISTEN for PUMP PRIMING !!... no probing or schematic necessary 👍🏼

[@carpediem939]

Hi, Honda Civic 2001 EX, no crank, no click from the solenoid on the starter, no noises at all when turning the key, but starter works testing it, and brand new battery, however, the snap in wire that goes to the starter (not the bolt one) gives like 200+ volts when cranking the car, when it should be giving 12 volts I think. I haven't tested the relay yet, and I don't know how to test fuses, I'm really new to this. What do you think I should do?

[@ScannerDanner]

I just watched it in 1080p full screen and I didn't see a spark at the fuse box. If it did, the only thing that would cause that would be a loose connection at the fuse, which could be possible. All I saw was my test light glare on the dash panel

[@spelunkerd]

How likely would it be to kick a fuse out and not know it? I think somebody at the school was yanking your chain, (grin). That's the best description of a main relay problem I've found (even if it wasn't, ha ha).

[@PapillonOne]

Great video, learned a lot!!

[@devillier2011]

great info, thanks!

[@davidserrano8463]

i need to check mine today. i having some problems with starting my car. something like this happened to my old honda accord

[@Ihavetruth22]

Kudos to you. good job man.

[@ScannerDanner]

ignition switch failing is my first thought. common issue on these.

[@carpediem939]

1/1 Wow, thanks for quick response. I have read that the green solid (no blinks) key symbol on the dash while cranking, and leaving on II after means that I should rule out an Anti-theft system problem, however I do have a fob with buttons that I have found out were a custom alarm put in by the dealer many years ago, but I just ruled it out because it scares me lol. So I guess I'll read up more on Relay and ignition switch problems. Thanks! Will let you know.

[@bcgobraves]

Great video! My relay looks exactly like the bad one, same two cracks and all. Shop wanted to charge me a ridiculous amount just for the new part and now I'll be soldering it for free. Not sure if you're still checking comments for this video, but I have a question: if one of these went bad while driving, would the car lose power and die, or is this relay just involved in startup?

[@PeteWebberDrums]

My 98 prelude died while driving 30mph from this problem

[@Achisachis73]

awesome video man! Where do you get the schematics? thank you

[@ScannerDanner]

eautorepair.adtrk.biz/?a=10817&c=24&p=r&s1= This is the DIY version of the same service information that I use

[@sity620]

Awesome videos Dan always make good videos I feel dumb asking this but I wish you would have shown us where you unhooked the controller from because I can't seem to find mine at all and I don't have anything that looks like that thing that you tested some of us could use an example of what it looks like and where it's located on most cars and since you didn't show the location of the thing that you tested maybe you can test an injector to show us that cuz I can't even get past the first step on this cuz I don't even know where that wire sensor is that you talking about I can't find it without . Your videos are very informative but I do not like how you did not show where you got that way or from you kind of point over your fingers but that doesn't help somebody like me that doesn't know their way around the engine some stupid reason I Google the layout and everything like that in there is not something online to show me exactly where it's at

[@ScannerDanner]

exactly

[@brandonknight7240]

So annoyed with my 99 accord, thought it was the main relay and replaced it with a new one from oriellys, did not fix it so I replaced the fuel pump and that didn't fix it either, my car runs good in the morning until I get where I'm going but when the engine is warm and I try to restart it ? It wont start, and a couple of times it did start then died going down the road and left me stranded for 30 minutes or so, I'm wondering if my issue is the immobilizer or ignition switch or key? Because the green key light flashes 5 times after I've pulled out the key

[@axenz1]

Wow ..thanks .. I learn from it

[@ScannerDanner]

+axenz axtiz cool man

[@DreCL32]

I have a 2003 honda accord ex . 2.4 I was driving and all of a sudden the car stalled on me . I tried to crank it a few times and it started and cut back off in like 5 sec and after that it hasn't started yet. After I try to crank it there is a buzzing from the ignition until I turn it back to the 1 position. Also when I turn to the 2 position the "D" gear indication comes on for a few seconds and then goes off. Any suggestions would be greatly appreciated . I changed the ignition switch but that did not help.

[@smileyrod11]

HEY DAN IS THAT 4 ALL HONDA AND NEW HONDA

[@MuseR.]

I had the white with green not light with a test light. So i got a new main relay and nothing. Still no crank no start. What's the problem now? I checked the fuse for it and it won't light up with the test light either. Switched the fuse with a known good fuse that lit up and still no light. Could this be a wiring issue? Any help is appreciated

[@arctican7483]

GOLD!

[@javieraviles4577]

Hi ScannerDanner great video by the way I had a question I'm trying to figure out why my 2001 Honda civic ex will crank but won't start. Let me start off by telling you that someone tried to steal my car but failed and even though they didn't steal it they cut all the wires on the driver side under the dashboard. My question to you is when someone does cut the wires below the dash driver side did they short my PCM and I have to replace it? Or is it the PGM Fi main relays that I need to replace and that's it? I just need some sort of direction if where to go with this.

[@gregscheyd4131]

First let me tell you that I'm not a mechanic by any means , but we might be in the same boat ... my problem is a no Crank, no start but I think what I have to say still applies ....the IMMOBILIZING SYSTEM ( ANTI - THEFT ) in my 2005 Honda crv DISABLES THE FUEL PUMP , FROM WHAT I UNDERSTAND . AND WHEN I PUT MY KEY TO THE ON POSITION , I DONT EVEN HEAR THE FUEL PUMP PRIME FOR 2 SECONDS OR SO ... I FIGURE somewhere between the fuel pump and pressure regulator , injectors , PCM FI MAIN AND ALSO PCM FI 2 is the problem , apRt from fuses , relays and wiring connections ....they cut all the wires probably to disable the ANTI- THEFT IMMOBILIZER . I DISCONNECTED MINE ON PURPOSE BECAUSE I THINK IT IS WHY MY FUEL PUMP IS NOT PRIMING .... IF YOURS IS CRANKING BUT NOT STARTING , THE FUEL PUMP PROBABLY IS PRIMING ... for me , I need to figure out how to bypass my immobilizer ???????

[@gregscheyd4131]

Take EVERYTHING I SAY with a grain of salt , but I am almost positive it is not the PCM , OR EVEN THE RELAY , IF IT CRANKS BUT DOES NOT START .... IF IT CRANKS , THE FUEL PUMP IS PROBABLY PRIMING AS IT SHOULD , WHICH MEANS THE RELAY IS DOING ( AT LEAST PART OF ) ITS JOB , which means the PCM is doing part of its also . I would also pretty much rule out the IMMOBILIZER , BECAUSE IT CRANKS BUT DOES NOT START ....... BELIEVE ME , I have been trying diligently to figure this out for over a year now : I want my CRV BACK !!!!!

[@gregscheyd4131]

BY THE WAY , I don't make ANY MONEY ,so I try to solve all of my problems without the aid of MONEY : so you can just imagine how much I greatly APPRECIATE PAUL DANNER , AND THE LIKES OF HIM : ANGELS , GOD-SENDS , IF YOU ASK ME ...!!!!

[@mckoylach1622]

Hello Paul, I have an 02 Acura type S,where is the fuel pump relay and the main relay located? Starting problem

[@ScannerDanner]

www.google.com/search?q=where+is+the+fuel+pump+relay+on+an+02+Acura+type+s&rlz=1C1GGRV_enUS751US751&oq=where+is+the+fuel+pump+relay+on+an+02+Acura+type+s&aqs=chrome..69i57.2538j0j8&sourceid=chrome&ie=UTF-8

[@BayAreaMCs]

I have the same 98 prelude and i suspect something with the main relay after i scanned it for trouble codes and got p0505 for Idle air control system. Also after checking the live data, i noticed the STFT was fluctuating around -20% on average obviously telling me it has a very rich condition, checked O2 sensors and they are working fine. I then noticed when i turn the key to the run position, the fuel pump will prime but not shut off until i either start the car or turn the key to the off position. So my question is what could be the cause of this, i was thinking it has to be an issue with a switch in the PGM-FI main relay staying closed, or the relay itself failing causing the fuel injectors to stay on too long causing the rich condition, as well as the fuel pump and iacv issues? Car has over 200,000 miles on it and 120k on the motor

[@ScannerDanner]

Two separate problems my friend. The fuel pump runs continuously while the car is running and will NOT cause your rich condition. Even with the key on and the pump running, this will NOT cause any fuel to get into the intake as the injectors are normally closed solenoids. Attack your rich condition and your idle control fault code first. Hope that helps.

[@BigD1395]

I guess really my question is this Paul, where are you pulling all of your wiring diagrams from? Let me guess some other paid program like Mitchell on Demand?

[@ScannerDanner]

Exactly, it is ShopKey, which is Mitchell On Demand and it is not cheap. We have a nice sticky thread on my forum on where to get diagrams for you guys, some free, some paid, nothing pirated. www.scannerdanner.com/forum/post-your-repair-questions-here/16-need-service-info-check-here.html

[@jms-ee1311]

I soldered the ones that had cracks and when I reconnected it to the harness it was working fine. I didn’t drive it around right away and after a couple of hours i tried to start it again but it doesn’t start anymore. It just cranks. Did I pop a fuse? The check engine light doesn’t turn on momentarily as I start the car.

[@ScannerDanner]

You may have? Check all your fuses for sure and then recheck your solder joints and make sure you didn't cross any of them

[@jms-ee1311]

ScannerDanner I popped the ACG fuse under the hood. Thankfully an easy fix. Thanks for the reply

[@angelcollazo9027]

Hi, I want to know where the PGM-FI of the 2008 honda fit is located

[@ScannerDanner]

If it has one? It may be called something else in 08. Pretty sure it is.

[@ScannerDanner]

:-) sorry. feel free to ask any questions you like. I will do my best to answer

[@glasser2819]

It's really helpful when you tell us the way you go about troubleshooting with a schematic and "logical funnel" down to the key problem. 👍

[@DJDevon3]

I can't find a single video where you cover wire or solder selection for repairs. I've been using some cheap autocraft solder from a parts store and it's god awful to solder small joints with. I've found that tin/lead solder is 10X easier to solder small electronics but isn't good for engine bay use because it will rust away. I feel like this stuff would be a great topic for you to cover for the guys who are just starting out that have never soldered a thing in their life or are having problems with solder flow even while using flux and tip tinners. Yeah it's easy to solder with big wires and rosin core but even in automotive you're not always soldering large gauge wires or large joints. Sometimes you have to do repairs on tiny joints and that's where wire and solder selection really plays a part in time efficiency. I spent 3 hours trying to repair something with crappy autocraft solder! 3 hours because the solder just wouldn't stick right and burned the wires in a losing battle keeping the wire and tip clean. Once I used some better quality solder I fixed it in 2 minutes. For an automotive electronics channel I was quite surprised to see you don't have a video on this subject. You're still my #1 favorite channel. God bless you and all in your family.

[@ScannerDanner]

Thanks brother! I'm not sure that I do. I know I soldered many, many times in my videos but nothing solder specific. Post this to my forum bro. Hope to see you there scannerdanner.com/forum.html

[@ScannerDanner]

no prob at all

[@ScannerDanner]

thanks :-)

[@chriscanty8214]

I have a 91 honda accord with a no start issue checked for spark it's good sprayed starting fluid into the tube that leads to the throttle body it acts like it wants to start when I hooked up my fuel guage didn't have any fuel spray out could the main relay not be letting the injectors fire shouldn't I have some fuel leakage?

[@ScannerDanner]

I think these videos will be helpful for you. Let me know kzbin.info/www/bejne/bHSwi2edbdNjfLM kzbin.info/www/bejne/iYbbkpqFdruGa68

[@WildPyro341]

I took the relay out, soldered ALL the points on the board, and placed it back but the car STILL does not start in the heat/after it rains until I cycle the power 3-4 times. What else could be the problem??? I had a brand new fuel pump installed along with a brand new distributor. 1996 Accord LX 2.2L Sedan.

[@ScannerDanner]

You have to find out what you are missing when it doesn't start otherwise we are just guessing on what the problem could be. Ignition switches are also common, but I'm not telling you to replace it. We have to prove it first.

[@WildPyro341]

Physically, all the parts are there. The mechanic couldn't even figure out, told me to bring it to Honda to run a computer diag. Could it be the computer? In my dash, when I turn the key to "On" the check engine light comes on and stays on when the fuel pump doesn't turn on. But when it DOES work, the [D] on my dash lights up green and the check engine light turns off and the car starts no problem. Just got $1300 worth of work done to the car and it still doesn't start... :-(

[@23nesto23]

2001 accord v6 4dr car shuts off coming to a stop and sometimes waiting at a stop light it shuts off???

[@uke4958]

23nesto23 - i see this is old comment from you - but I have same problem and did the main relay fix it for you??? Please reply soon

[@mrodriguez5259]

Inteligent

[@jordanfort4294]

Sir when you test the IACV yellow wire is this key on or not? thanks

[@ScannerDanner]

Yes, key on my friend

[@jordanfort4294]

ScannerDanner hi friend when i tried to test the yellow wire using test light the light is dim not brighter?

[@ScannerDanner]

@@jordanfort4294 Then you have a voltage drop on that circuit

[@jordanfort4294]

ScannerDanner what does it mean sir? thanks

[@ScannerDanner]

@@jordanfort4294 high resistance, corroded connections, break in a wire (not a full break), you need to trace that circuit and you will need a good wiring diagram eautorepair.adtrk.biz/?a=10817&c=24&p=r&s1=

[@jameslynn4904]

can this still be the problem with an intermittent NO CRANK no start

[@ScannerDanner]

+James Lynn no, the main relay does not control the starter motor. I have some videos on no crank conditions kzbin.info/aero/PLAFYVCyenqcpZM-kQg5MUX0OvrIPSirz5

[@xfatal_hdx251]

What if it only doesnt start when cold outside like temp wise anything below 35 it will just crank and not turn over. I have a 98 honda prelude. New fuel pump within a month after old gave out, fuel injectors clean and spraying like new with replacement pressure and orings, fuel filter new, 42 psi when checked. New Ngk plugs, wires, rotor, cap, ignition coil, valve cover gasket, no vacuum leaks, entire cleaning and regasketed the intake manifold, tpms had a crack which was replaced and relearned, the throttle body was regasketed and cleaned, the air intake filter new, ignition switch new, air intake temp new, great spark, and ignition timing, ect reading properly, icav new, the fitv regasketed and cleaned, bad terminals replaced, brand new honda battery due to other being old and giving out. And im sure theres some other things missing but after all that the darn thing still wont turn over in winter. Oh and main relay is pulled as im typing and seems the solder joints are good! I dont know what else it could be other than pcm but reads live data correctly or am i missing something to look at.

[@Peace-io7qu]

Static picture?

[@ScannerDanner]

@TheDroman37 thank you very much!

[@JUDGERAMBO]

The kick panel cover is missing

[@450-v9w]

i can't find where is my main relay located on my civic si 2007 please someone help me

[@wilsongerman374]

So. If the main relay is not the problem, we must check at the fuse box !! Great !!! But where go to, if the isn't getting to the fuse box neither?

[@ScannerDanner]

ignition switches are common failures on these systems, they key is having a good wiring diagram eautorepair.adtrk.biz/?a=10817&c=24&p=r&s1=

[@treblarefils]

Cool !

[@GinjaNinja4905]

KENNY POWERS!

[@ibrahimfirat4493]

👍👍👍

[@Valde3333]

2:10 I have couple of intermittent faults with fuses

[@lawnside82]

the real question is who kicked that fuse out and how?? and wouldn't more that just that fuse fall out?? that's kinda weird..

[@typhoon320i]

10:26 Hahaha.... There's your problem!

[@jaychry]

Well...I can't say "that was easy"....

[@uke4958]

Anyone - please reply - is this only for Honda's that do not START? because my 99 Honda Accord wants to STALL when I stop at a red light or stop sign or when making turns. PLEASE reply soon - DO NOT want to go to mechanic and get ripped off! Thanks in advance !

[@ScannerDanner]

not all mechanics will rip you off So does it not start or you have a stalling problem? Two separate issues.

[@uke4958]

It wants to stall whenever I am driving and need to stop at a light or stop sign. I checked the main relay and it looks in great shape - even checked with microscope for cracks, etc. Should I replace main relay anyway? Car starts just fine. Thank you ps - I am very new to car repair.

[@jimjambananaslam3596]

Uke - It could be a dirty idle air control valve that's getting stuck. They're easy to take off and you just clean them with a 5 dollar bottle of carb cleaner. Probably will want to reset the ecu after that. Also, buy a bottle of fuel injector cleaner and put that in your tank next time you fill up. It could also be a vacuum leak, look up how to check. Most mechanics aren't looking to rip you off, they want your return business and there's always a lot of competition in town. That said, always do a google search and try any easy solutions before going to a mechanic, they won't try to clean or repair parts, they just replace them, so it's worth the effort sometimes.

[@hugeshows]

Last night I fixed my neighbor's 97 3.5 RL before seeing this video. It had cracked solder joints AND a missing fuse. Bizarre.

[@ScannerDanner]

that is weird

[@hugeshows]

@@ScannerDanner Today he was out pressure washing it. It sat for almost 9 months! Anyway, I was thinking about doing a video about this but seems like you've got it covered!

[@hugeshows]

Oh one other thing I should mention for future reference is that there was another symptom that cropped up - I hooked up my cheapo OBD-II scanner and it wasn't receiving any power from the port. That problem went away after replacing the missing fuse #6 which is what was supposed to give power to the PGM-FI unit on pin 3. According to the Chilton book, that 20A fuse supplies both the 2nd half of the PGM-FI relay that feeds the fuel pump but also the powertrain control module. Unless that port only works when the engine is running, then it seems that getting no power to the scanner might be a good indicator of that circuit having failed in some way. (97 Acura 3.5 RL) I should also mention that I have seen problems related to cracked solder joints on many Mercedes vehicles too, and have done videos about that. This seems to be a common failure mode whenever a heavy component like a relay is mounted to a circuit board using only the weak solder electrical connection as the mechanical connection as well. Years of vibration just break the soft solder at its stress points. Many sudden and intermittent failures can be fixed by re-soldering joints on cars that have this type of circuit board construction. Adding an electrically inert and acetic acid free adhesive to stick the components down and hold them fast to the circuit board, where feasible, is a more permanent fix than solely re-soldering the joints which are not up to the task of supporting the full component over time.

[@ScannerDanner]

Do it anyway!

[@SombraEnMovimiento]

It would die driving, since the fuel pump will be shut down.

[@evoixdelaluz]

there's an easier way to find out if your pgm main relay is working properly, I rather save the time and not do it your way,

[@andrewdbreck]

Do you think this would be the cause of my 2001 Prelude suddenly shutting off while I was driving it one day? I had to hit the brakes kinda hard and it just shut off. Couldn't start it again. I'd excitedly go visit it right now for that answer, but it's 6 hours away :/ Thanks. Oh. My mechanic said to Google "No Injector Pulse" and this is the rabbit hole I find myself down. Edit: I put up a link of me trying to start it back in August. Hopefully you're still active on this channel! streamable.com/t2u8gs

[@dilloncassidy3760]

can someone make a video how to get it out of the case I'm having a really hard time plz message me if you do will be greatly appreciated. I can even PayPal you 10 bucks.

[@anthonyalvarado7230]

dillon cassidy did you ever figure it out man?

[@anthonyalvarado7230]

dillon cassidy I used a tiny flathead to pry it out while pulling the casing in the opposite direction.

[@dilloncassidy3760]

+Anthony Alvarado yes I did.and then I sold the car.

[@joachimjohan1215]

"THESE ARE NOT THE PINS YOU ARE LOOKING FOR..."

[@laurenvillegas6103]

Can u tell me in plain english pls? Im a girl