BL Mazda 3: Alternatives for when you've lost your last key

When you've lost your last key, you have two choices: either get a locksmith to cut you a new key, or go to a wrecker and buy the parts to transplant in a good set of keys. This video explores the second option.
The software I am using is called Forscan. You can download it from forscan.org/.
Camera-goddess: Brittany.
The Dude: Paul in Perth.
Tags: BL Mazda 3 2009 2010 2011 2012 2013 security lost keys transponder ignition

[@user-yd4yl4ht1z]

Thanks Paul ,this video was very helpful ,I had put the job of for months,after watching your video I pulled both dash boards out and refitted the good one in about 4 hours Thanks again Paul

[@rufustaylor833]

Thanks for the hands on knowledge

[@MASSIVEPUFFSGHEE]

Absolute legend the car world needs more useful video when it comes to the programming world

[@user-ob3ki8ih7s]

Thanks, Paul! Awesome video!

[@BlueSky-ey4wt]

Thanks so much for sharing your knowledge

[@PaulinPerth]

You are very welcome. I love sharing. Paul.

[@rayw9067]

The amount of money my local Mazda want for this job is absolutely criminal I’ll be doing the replacement myself for sure

[@PaulinPerth]

So....... is that a thank you? Just while I think of it, there is one other elegant way to solve this; as long as you kept that little silver keytag from when the car was new. That keytag has the key serial number written on it. If you quote that number to any auto locksmith, then they can make you a key that will fit your existing barrel. This avoids having to change the barrel, barrel housing, and driver's door lock. Then all you need to do it program the transponder codes into the BCM, which the locksmith can do, or you can do using my instructions and Forscan with OBDLink. Paul.

[@rayw9067]

@@PaulinPerth 100% a thank you! Paul I’m a mechanic by trade, diesel though heavy road trans so cars to me are foreign-ish! This is a simple explanation of what needs to be done and even your comment is simple but these dealers continually quote astronomical prices and babble and bullshit so customers think they have no other choice!!! This is brilliant what your doing mate keep it up! Thank you for your advice it’s greatly appreciated mate

[@PaulinPerth]

@@rayw9067 Thanks Ray. I appreciate it mate. Paul.

[@stevejette2329]

ray - YES !!! I am helping a lady who has lost her keys, has only the valet key. The locksmiths are outrageous. Local mechanics want $170 per hour. She is on disability.

[@user-ml4tq8mo4o]

Thanks Chief🙏 It's very helpful indeed

[@gonzaleznorte88]

Thank you I bought a Mazda without keys and Mazda doesn’t carry them anymore I’ll try this thanks again

[@breakingthemasks]

Liked and subscribed, bet effective request at the end there mate 👍 You definitely provided value there

[@Tecto764]

Legendary

[@stevejette2329]

For 100 years, cars worked just fine with simple metal keys ... these things they call "keys" are an invitation to getting locked out, alone, at night, in the cold because the key battery is low. And the EXPENSE is ludicrous. Locksmiths laugh all the way to the bank.

[@Sonu___Joseph]

I lost the key ( last key ) but door is unlocked position so I can enter .

[@hycron1234]

What about a situation where you have two keys that are keyed to the doorlock and ignition, but the second key no longer starts the car, can I simply wipe the keys out of the car and readd them? or can I add a new key using Forscan? (2004 Mazda 6 GG)

[@PaulinPerth]

I think that either of those methods would work. Go for it.

[@danielchen9841]

Greate vid❤❤❤

[@je-g-gcapone1167]

What if i cant communicate with bcm, like my obd2 port got some issue and im not able to find the problem soh im trying to bypass everything to start my engine but the immobiliser dont let me do this

[@MahmoudMazda]

Thanks Paul, excellent. Can you program the remote as well?

[@PaulinPerth]

Yes Mahmoud. If you Google it, then you will find it. Paul.

[@HustlrG]

Hi Paul thanks for the great video! Question: do you know what transponder chip it uses? 4D63? 80bit 40bit?

[@PaulinPerth]

Hi @HustlrG, I don't know. If you find out, could you please post it here? Paul.

[@kennyfmt510]

Could you just get 2 new keys cut and use forscan to program them to the car?Instead of replacing everything?

[@PaulinPerth]

Yes. That would work.

[@kennyfmt510]

@@PaulinPerth I’ve done it but when I was on forscan and went to erase the old keys and program new ones it erased the old ones and when I try to program the new keys it says “no key detected” do you think it’s an issue with the immobilizer coil antenna?

[@kappy5003]

Paul is this relevant to 2010 BT50? I have a part key with blade and chip that did work now doesn't..

[@mosesmakaringi9366]

Hi Paul, mine is a bit different it's Mazda 3 bk 05-09, doesn't shut off with a key and the dashboard lights stays on and engine running even when the key is removed

[@PaulinPerth]

Wow! That's quite interesting. The first place I would look is the ignition switch at the end of the ignition barrel housing. With a multimeter, check if the ON position retains a circuit when the key is in the OFF position. I suspect it does. If so, then you need a new ignition switch. Paul.

[@mosesmakaringi9366]

@@PaulinPerth Thank you so much, I will definitely do that.

[@tatianaplays3741]

What program you were using to program keys?

[@PaulinPerth]

The software I am using is called Forscan. You can download it from forscan.org/.

[@dricusvanjaarsveld6334]

This is amazing. Thanks Paul. I was wondering if I can ask a question. My wife has a 2008 MPV with a keyless remote. It is by far the worst keyless remote I have ever had. We are onto our 4th key and Mazda charges a arm and a leg to replace them. We have now lost the blade out of the key and I am thinking of replacing the keyless fob with a standard blade key as in the video. Would the process be the same with the proximity key? Thanks for the video any way. 👌

[@PaulinPerth]

I've got no experience at that particular operation. Sorry. I can't help. Try a good auto locksmith that is not Mazda.

[@eduardomunoz3154]

Why you don't read the key cut code form the cylinder and cut the key and program? 20 minutes job.

[@PaulinPerth]

Well, yeah, locksmiths with the right tools can do that. Yes.

[@DMRH69]

G'day Paul......... DE-series M2. Does it work the key system the same way as the BL-series M3...? If the BCM already has 3-keys programmed. You have lost 2-keys & have only 1-key left Now you want to program in a new (2nd) key which is physically the 4th key. Can you reset the "3-keys" feature of the BCM without a scanner or lap top program....?

[@PaulinPerth]

I've never tried, and I don't have a DE to try. But here is a tip to how I got to know so much about Mazdas. When I didn't know the answer, I researched what I could online, and if that didn't work, I just got in the car and had a go. You might want to try that.

[@2thepoint325]

Can you program a used transponder from other's car?

[@PaulinPerth]

Yes. That's what I do in this video. That whole key set, including the transponders in the keys came from a previous BL that I wrecked.

[@edenmakale7880]

​@@PaulinPerth hi...my mazda3 cluster is not working properly rev count nd speedometer, when i try to replace cluster the car is not starting....help

[@PaulinPerth]

@@edenmakale7880 Replacing the cluster will not work because the VIN stored in the EEPROM of the IC does not match the rest of the car. The only way you are going to get that to work is to hand it over to a Mazda dealer.

[@michaelbarrett8803]

Just pay the lock smith???

[@PaulinPerth]

Yes, that is an option.

[@Sonu___Joseph]

Which software is used to programming ?

[@PaulinPerth]

The software I am using is called Forscan. You can download it from forscan.org/.

[@HOOD_FELON]

Would this work on a 2008 Mazda BT-50?

[@PaulinPerth]

I don't know. But why not just have a go?

[@garylough8774]

Can u change that and the ECU and not have to program

[@PaulinPerth]

I've never done it to be absolutely sure, but I suspect that if you changed the barrel, keys, BCM, ECU and instrument cluster that have all come from the same car, then it might work. If you end up doing it, can you please post back and let me know how it goes? I am curious. Paul

[@rysiukr]

Hi Paul, Great tutorial videos. My son's 2012 Mazda3 starts when the clutch is depressed and the key is in the ON position, or when the key is in the ON position and the clutch is depressed. ie. no need to turn the key to Start. I suspect faulty or contaminated ignition switch. How do I prove it? oh. and the battery is losing charge if the car is not started for more than a couple of days.

[@PaulinPerth]

Hi Rysiukr, I'm not an auto electrician, but for what it is worth, I can only think of two possibilities: the starter motor relay being stuck in the ON position, or the ignition switch having bridged the ON and START key positions. Testing the relay hypothesis is pretty easy: go to the fuse box in your engine bay and swap the starter motor relay with the aircon relay. They are identical. If that fixes the problem then replace that relay. If it doesn't fix your problem then I'd look at replacing the ignition switch. If you are in Australia, I can post both these parts to you. Let me know how you go. I'm curious. Paul.

[@rysiukr]

@@PaulinPerth An overdue update from Canada. The relay was not the problem. So we disassembled everything down to the ignition housing and popped off the ignition switch. We then used a multimeter to test continuity between various combinations of the 8 pins (based on a schematic we found online) with the key in the four possible positions (inserted, ACC, ON, Start) and found that two pins that should have 0 ohms between them (ie connected) only when the key was in the start position were also connected in the ON position. Ta da. Faulty ignition switch. Seeing as we had gotten this far, there was no point in not opening up the ignition switch to see it there was something obvious causing the problem. The internals of the switch were quite simple... just two metal disks that spun when the key was turned... and the only thing that looked suspicious was the amount of grease covering the two metal disks. So we cleaned up the disks, reassembled the switch, reinstalled it and... unfortunately had the same issue. So it looks like a new ignition switch is in his future. Thanks again for the video and the advice.

[@louisstroomer4220]

Hello Paul, from the Netherlands. Question: if you would change the whole lock unit, and use the new key together with the new transponder receiver, would there still be a problem? Thanks, Louis

[@PaulinPerth]

Hi Louis, I'm a little unsure by what you mean. I think what you are asking is whether or not it would work if you changed the keys, key barrel and transponder ring. If this is your question, then yes. You will still have a problem. You do not have to change the transponder ring (receiver). It is a passive device. It does not contain any data in it. It purely reads the code of the transponder in the key and sends that code to the Body Control Module (BCM). What you do need to do is write the new codes for the new transponders in your new keys into the BCM. To do this, just follow the instructions in my video. You need Forscan, which is free to download and install, and free to get a 30 day trial key that enables all features including key programming. Paul in Perth.

[@louisstroomer4220]

@@PaulinPerth Thanks for your reaction. I didn't want to spend a lot of money on a car I need to sell anyway, so I went for the simple solution. Cut open de old key and took the transponder out, and installed it in the 'new' key carefully. Just a little bit of glue to close it, and you wouldn't know it happened. Car starts fine now! Thanks again, Louis

[@PaulinPerth]

@@louisstroomer4220 Great work Louis! Well done my friend. Paul.

[@user-dx8qc9hp7n]

what computer is the key stored in because i need to replace my ecu and wanted to know what computer they are stored in

[@PaulinPerth]

Easiest solution: get your replacement ECU programmed at a Mazda dealer. Second easiest solution: de-solder the EEPROM chip from your failed ECU and solder it onto the replacement ECU. Possible alternative: read the old EEPROM and overwrite the new EEPROM with those values using an EEPROM programmer. Hardest solution: use a matched working set of ECU, BCM, Instrument cluster, barrel, keys and driver's door lock. Paul.

[@user-dx8qc9hp7n]

@@PaulinPerth ya I was gonna try buying a used ecm and bcm with the keys and take the chips out and put them in mine so I didn’t have to change out the locks