Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
A technician may comment of intermittent CEL, DTC's or No communication with various modules. This may be caused by a short to ground of the vehicle wiring in the engine harness.
The harness may chaff in the area of the Canister Purge Solenoid attachment bracket, causing an intermittent shorting to ground. The harness routing forces the harness into the edge of the bracket. This bracket is present with any Ecotec engine. The Purge Solenoid bracket may have a sharp edge from the manufacturing/shearing operation. If any DTCs are setting consistently, perform the eSI diagnostics and repair as necessary. If the eSI diagnostics do not isolate the concern, inspect the engine harness for potential shorts to ground at the EVAP purge valve bracket on the side of the cylinder head. Then repair and reposition the circuits/harness as necessary.
It sets when the difference between the desired CMP actuator angle and the actual CMP actuator angle is greater than 6 degrees for greater than 13.5 s.
The powertrain control module (PCM) or body control module (BCM) diagnose a condition preventing the engine traction control and sends a serial data message to the EBCM indicating that torque reduction is not allowed. The PCM or BCM will typically set a DTC and the EBCM will set this DTC.
This DTC is for information only. As an aid to the technician, this DTC indicates that there are no problems in the ABS/ETS system.