Circuit/System Verification
- DTC P15F9 is an informational DTC. Diagnose all other engine control DTCs prior to DTC P15F9. Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- If there are no other engine controls DTCs, diagnosis is accomplished by looking for an intermittent CAN circuit fault. Refer to Scan Tool Does Not Communicate with High Speed GMLAN Device .