GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The PCM monitors various parameters and will not allow traction control operation if any parameter falls below a specified value.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0240 Powertrain Control Module (PCM) Traction Control Not Allowed

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The PCM detects a malfunction and then causes TCS shut down until the malfunction has been corrected.

Action Taken When the DTC Sets

If equipped, the following actions occur:

    • The electronic brake control module (EBCM) disables the TCS for the duration of the ignition cycle.
    • A DTC C0240 is stored.
    • The TCS is disabled.
    • If the TCS is again allowed to function, the indicator will be turned OFF, but the DTC will be stored.

Conditions for Clearing the DTC

    • The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
    • The electronic brake control module (EBCM) automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Test Description

The number below refers to the step number on the diagnostic table.

  1. This step checks if DTC C0240 resets.

Step

Action

Yes

No

Schematic Reference: Antilock Brake System Schematics

Connector End View Reference: Antilock Brake System Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Turn the ignition switch to the RUN position, with the engine OFF.
  2. Using a scan tool, read the antilock brake system (ABS)/traction control system (TCS) DTCs.

Are any other DTCs set?

Go to Diagnostic Trouble Code (DTC) List - Vehicle

Go to Step 3

3

Is DTC C0240 set as a current code?

Go to Step 5

Go to Step 4

4

  1. Using the scan tool, clear the DTC.
  2. Remove the scan tool from the data link connector (DLC).
  3. Carefully drive the vehicle above 12 km/h (8 mph) for several minutes.

Did DTC C0240 set as a current DTC?

Go to Step  5

Go to Diagnostic System Check - Vehicle

5

Perform the Powertrain OBD System Check. Refer to Diagnostic System Check - Vehicle .

Did the vehicle pass the OBD System Check?

Go to Step  6

Diagnostic Trouble Code (DTC) List - Vehicle

6

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step  2

System OK