GM Service Manual Online
For 1990-2009 cars only

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B0025 Engine Start Without Slip Ring Communication

Conditions for Setting the DTC

Engine Start Without Slip Ring Communications--During key reading the body control module (BCM) checks the engine speed from the engine control module (ECM). When the engine speed is above 500 RPM, the BCM will start a counter to track the number of times the key has been powered up without a valid message being received. When the counter exceeds 20 the DTC is set. This corresponds to 5 seconds of invalid key communications after the engine has been started.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step tests whether the condition is the module, the system, or a related condition.

  2. This step tests if the condition has been corrected or identified as specified in the supporting text.

Step

Action

Yes

No

Schematic Reference: Theft Deterrent System Schematics

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, monitor the DTC Information for DTC 25 in the body control module (BCM).

Does the scan tool indicate that DTC 2 is current?

Go to Step 4

Go to Step 3

3

Most occurrences of this DTC are caused by a faulty slip ring to key contact. Review the diagnostic aids and operate the vehicle to reproduce the fault.

Did vehicle operation cause this DTC to set?

Go to Step 4

System OK

4

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within normal operating conditions.

Does the DTC reset?

Go to Theft Deterrent System Inoperative

System OK