I have a 2013 2.5L Chevy Malibu LS, which had a bad ECM (Water got in and destroyed part of the board causing random sensor errors and randomly killing the car when driving, randomly deciding not to start, and causing the rpm tachometer to cease to work unless car was restarted). I ordered a new ECM for the exact model of my car, same part number and they programmed the VIN correctly however despite it being installed correctly the car refuses to crank and start, no security, no other lights beside check engine light, the only code that comes up is a check engine light code for Crankshaft Position Relearn which in normal considering it's a new ECM. I'm stumped at why the car has a NO START condition. Anyone have any ideas? I confirmed it had to be the new ECM causing this issue as I reinstalled the old ECM and it started up like it did before.

  • The new ecu needs programming to the car - take it to the dealer and they can "marry" the ecu to the car.
    – Solar Mike
    Apr 9, 2020 at 10:00
  • Isn't that what VIN programming is? Apr 9, 2020 at 10:20
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    You said it "will not crank" ... does that mean the engine goes around and it won't start, or that the engine won't go around at all when you twist the ignition key to the start position? Apr 9, 2020 at 10:36
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    What the car does is the dashboard lights up when put to the run position as if it were going to work and when you twist he key to spring loaded start position the dash shuts off as if to were going to start but nothing else happens, the starter does not engage or move. The engine does not try to go around at all. Apr 9, 2020 at 10:59
  • FYI - "the starter does not engage or move. The engine does not try to go around at all" - That means it does NOT turn over. If the starter turns the crankshaft then that is called turning over.
    – Alaska Man
    Apr 9, 2020 at 20:23

2 Answers 2


Your immobilizer is active.

After flashing the replacement ECU with proper VIN and calibrations you need to also program the immobilizer to store the sync codes in the replacement ECU. It needs to be done while connected with your immobilizer module and key so can not be done remotely like your supplier did for flashing the VIN and calibrations.

Turn your key to "ON" position and look at your instrument cluster, You will see a padlock symbol lit solid.

Are you located in US or elsewhere? In the US there is a manual procedure you can do. Elsewhere then you must use a good diag tool.

The dash going out during crank is pretty common on GM, I would only investigate further if you still have trouble after programming immobilizer.

Programming (US ONLY)

  1. Set up a battery maintainer on car.
  2. Insert key and turn ignition to "ON" (do not crank") leave there for 10 minutes. (not a second less)
  3. Turn key off then back to "ON" (do not crank) and leave there for another 10 minutes.(not a second less)
  4. Turn key off then back to "ON" (do not crank) and leave there for a final 10 minutes.(not a second less)
  5. Turn key off and wait 10 seconds. DONE.

Normally the security light is solid during the 10 minutes and when you see it go out then its ready for next step. If the light never turns off just switch after 10 minutes but usually this means something is wrong.

  • I'm located in the United States. Which manual procedure are you talking about. Also there is no padlock symbol lit solid when in the on position. But I know it works because it come on during the bulb check Apr 9, 2020 at 12:47
  • If no padlock symbol then it sounds most likely that the replacement ecu is no good but try the immobilizer programming first. I'll edit it into answer.
    – narkeleptk
    Apr 9, 2020 at 12:51
  • So I've tried PASSLOCK 3 key relearn before and that did not work as the padlock symbol did not appear once and the car did not start after the relearn procedure. The company sent relearn instructions but did not mention which Version of immobilizer I have. It says for VATS system I do not need to reprogram and the instructions for PASSLOCK 2 AND 3 are very similar. Apr 9, 2020 at 13:05
  • The name for the 13 system escapes me (its none of those) its first Malibu they switched immo to the bcm so don't think they call it passkey any longer. but the name is no big deal. If you did the procedure already like I said and your old pcm still works then the only explanation is: replacement ECM is bad or they programmed wrong calibrations. Your old ecm should not work after the relearn procedure.
    – narkeleptk
    Apr 9, 2020 at 13:11
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    So I found the answer. It was properly flashed but these Chevy Malibu ecms have different versions for the same engine. The company sent me a wrong version and I will be sending it back in to get the correct one. Apr 9, 2020 at 19:58

So after some research I've discovered these Chevy Malibu ECMs have a part number, a service number, and a hardware code. The hardware code is identical to the part/service number and may appear to be the correct ECM but is heavily different. It's the middle 8 numbers at the top and needs to be exactly the same as your new ECM. Also there is a 4 letter code at the top right that also needs to be the exact same for example my old ECM was ABMX but my new ECM was ABVT. When ordering a new ECM make sure ALL numbers match and check everything 4 times and have someone with a fresh pair of eyes check. Also always do proper research for your brand of ECMs.

Also as a side note for anyone who has a similar problem: The car has a VATS immobilizer system and does not need to be reprogrammed to the new ECM. As long as your new ECM is properly VIN programmed by the company your ordering it from or a dealership it should just work because of how a VATS immobilizer system works compared to a PASSKEY/PASSLOCK System.

  • If the service number of the ecm is the same then it can be flashed to match your car. This car does not use VATS. Vats is used on OLD GM cars where there is a visible black pellet resister built into the key. VATS hasn't been used since around 2003'ish Buick's and Cadillac's and your IMMOBILIZER 100% needs to be reprogrammed after the ecm has been replaced. I do these everyday for dealers and other mechanics. That is why I knew and told you it was bad when you reported there was no security light present.
    – narkeleptk
    Apr 9, 2020 at 22:25

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