C1239 Emission Rolls Test Active

C1239 Code - continuously with the ignition on and the Totally Intergrated Power Module has the emissions test mode bit set. If the Antilock Brake System (ABS) Module receives two in a row indicating that the Totally Integrated Power Module has been requested to activate the emission rolls test.

Possible causes C1239 Code

• Emission Rolls test enabled
• Antilock Brake System (ABS) Module
• Totally Integrated Power Module

Diagnose C1239 Code

Step 1. Verify the DTC is active

Turn the ignition on, with the scan tool record and erase the DTCs. Turn the ignition off, turn the ignition on. Using the scan tool, read the DTCs.

Is the DTC active at this time?

Yes, go to step 2.

No, go to ABS Intermittent condition.

Step 2. Emission Rolls Test enabled

Turn the ignition on, using the scan tool, under ''Miscellaneous Functions'' disabled the emission rolls test in the Totally Integrated Power Module. With the scan tool, erase the DTCs. Turn the ignition off and wait ten seconds. Turn the ignition on, using the scan tool read DTCs in ABS.

Does the DTC remain active?

Yes, go to step 3.

No, test complete, the condition or conditions that originally set this DTC are not present at this time.

Step 3. Antilock Brake System (ABS) Module

Turn the ignition off. Replace the Antilock Brake System (ABS) Module, perform the ABS Verification Test. Turn the ignition on, using the scan tool read DTCs in the ABS.

Is the DTC still remain active?

Yes, replace the Totally Integrated Power Module.
No, test complete.

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