I am having a problem with my 2012 corolla. I drove it out on a rainy morning at a point the car could accelerate and I parked, and I invited my mechanic who helped drive the car to his workshop. On getting to his shop the car refused to start. It cranks and starts but shuts off immediately. But you hold the accelerator flat on the floor, the car starts, but will accelerate and turns off immediately. We have checked the noozles, coils, plugs, airflow meter, and the situation did not change. Any suggestions please. The problem started on Saturday, and the car has not started till today

  • Do you think it has anything to do with the brain box
    – Ike
    Jul 8, 2021 at 18:18
  • Welcome to Motor Vehicle Maintenance & Repair! I don't know for sure, but it sounds like the ECU is not getting input for a needed sensor so shuts the engine down. I'd suggest since it is taking the input of the throttle right off the bat before it shuts down, that it's not the ECU. Something else is going on. Jul 8, 2021 at 20:20
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    If it starts when flooring the gas would indicate flooding problems. Floored gas pedal is flood mode on most cars. I would think your mechanic might put a fuel pressure gauge and an injector tester on it to see how much fuel is going or leaking through the injectors.
    – Jupiter
    Jul 9, 2021 at 13:19

2 Answers 2


Well, the car started today after much efforts. The ECM was the culprit. The car started immediately an uncoded ECM was installed to the car. The new problem now is how to programme this new ECM to work with the immobilizer to ensure the car safety. Any suggestions?


GM has several security programs for anti theft. A common theme with GM EFI systems using factory immobilizer systems consists of two modules 'married' to each other via a fuel password. The two modules are the engine ecm and body control module that runs everything else except the EFI system, air bags and antilock brakes. The EFI system uses a dedicated ecm or pcm, airbags have its own computer module and antilock brakes has its own abs/tc computer module. The ecm and bcm are married at factory assembly with a ten minute procedure. If one or the other fails, there is no such thing as plug n' play as the fuel password is the security pw exchanged between ecm and bcm. If one fails then the replacement is programmed by a GM dealer or licensed locksmith with appropriate scantool. At home, a diyer can marry the replacement in a thirty minute procedure without GMs scantool but loses remote keyless functions and odometer mileage (if the bcm is replaced with a used one). New replacement BCMs are programmed with mileage and existing remotes at the dealer or using an aftermarket clone of GMs scantool.

Toyotas may have a similar configuration but you'll have to ask Toyota or find Toyota forums with knowledgeable members having explicit info. The other alternative is subscribing to either Alldata.diy or Mitchell for online access to manufacturers service manuals. More info than Chiltons or Haynes.


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