For a complete wiring diagram Refer to Section 8WWhen Monitored:With the ignition on.Set Condition:A Cabin Heater (PTC) #1 error message has been received over the CAN bus from the Totally Integrated Power Module (TIPM).Possible CausesINTERMITTENT DTCDTC SET IN TOTALLY INTEGRATED POWER MODULE (TIPM)ENGINE CONTROL MODULE (ECM)Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.(Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)1. DTC IS ACTIVEThis DTC will set if the Engine Control Module (ECM) receives a message from the Totally Integrated Power Module indicating that a PTC Heater Relay DTC is present.Ignition on, engine not running.With the scan tool, Clear DTCs in the Engine Control Module (ECM).With the scan tool, actuate the PTC Heater Relay 1.With the scan tool, select View DTCs.Is the status Active for this DTC?YesGo To 2 NoRefer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure.(Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)2. ENGINE CONTROL MODULE (ECM)With the scan tool, select View DTCs in the Totally Integrated Power Module.Is there a stored or active PTC Heater Relay DTC present in the Totally Integrated Power Module?YesRefer to 24 - HVAC — ELECTRICAL DIAGNOSTICS for diagnostic procedures and for further possible causes.NoReplace the Engine Control Module (ECM) in accordance with the Service Information.Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - STANDARD PROCEDURE)