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Dave Nova
Dave Nova, Chevrolet Technician
Category: Chevy
Satisfied Customers: 19451
Experience:  ASE Master Certification. GM World Class Certification
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2003 Chevy cavalier: stay running..running fine..the engine turns

Customer Question

2003 Chevy cavalier, will not stay running. Was running fine, battery went dead (lights were left on), then charged the battery with a charger). Since then, the engine turns over fine, runs for about a second, then shuts off. Fuel pump does hum when key is in the "on" position and does pump fuel. Changed to brand new battery and fuel filter. Also, Theft system light does not light at all. When you start or even turn on ignition, the other gauges do not change (fuel level, tach). It does run a little longer spraying starter fluid into the air intake. Hooked Mac (auto) computer, but doesn't show as being hooked up at all. Any suggestions? Ignition lock cylinder or ECM? Thanks for any help you can provide!
Submitted: 8 years ago.
Category: Chevy
Expert:  Dave Nova replied 8 years ago.
Usually when the engine starts then dies, the problem is related to the Passlock security system. The most common problem with the Passlock system is the Passlock sensor which is built into the ignition lock cylinder. Check the fuse labeled MIR/DLC this fuse powers the data link connector for the scan tool connection.
Customer: replied 8 years ago.
The MIR/DLC fuse is good.
Expert:  Dave Nova replied 8 years ago.

You should then have power to the data link connector for the scan tool. Perhaps your scan tool will not work properly. Try the following procedure:


  • Turn ON the ignition, with the engine OFF.
  • Attempt to start the engine, then release the key to ON. The vehicle will not start.
  • Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF.
  • Turn OFF the ignition, and wait 5 seconds.
  • Repeat steps 1 through 4 two more times for a total of 3 cycles/30 minutes. The vehicle is now ready to relearn the PasslockTM Sensor Data Code and/or passwords on the next ignition switch transition from OFF to CRANK.

    Important: The vehicle learns the PasslockTM Sensor Data Code and/or password XXXXX the next ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.

  • Start the engine. The vehicle has now learned the PasslockTM Sensor Data Code and/or password.
  • Customer: replied 8 years ago.
    I had tried that yesterday and again this morning. No luck, the car still starts and stalls immediately. Also, the theft system light does not come on.
    Expert:  Dave Nova replied 8 years ago.

    The body control module (BCM) controls functions of the theft deterrent system and controls the security indicator. The most likely problem is a bad BCM. The BCM is located under the dash on the drivers side.


  • Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .
    Object Number: 763283  Size: SH

  • Release the body control module (BCM) wire harness retainer from the BCM bracket.
  • Disconnect the BCM electrical connectors from the BCM.
  • Release the lock tabs and remove the BCM from the BCM bracket.
    Object Number: 581535  Size: SH

  • Remove the BCM bracket nuts (2) if required.
  • Remove the BCM bracket (1) as an assembly if required.
  • Customer: replied 8 years ago.
    It was actually the radio! It was not a factory installed radio and the module that it was hooked to went bad and was tripping the computer.
    Expert:  Dave Nova replied 8 years ago.
    I am glad you found the problem. Thanks for using Just Answer.