Diagnosis And Testing - Positive Temperature Coefficient (PTC) Heater Unit

WARNING: This page is about a different car, the 2016 Dodge Durango. However, it is still accessible from the selected car via links, so may be relevant.

WARNING:

Disable the airbag system before attempting any steering wheel, steering column or instrument panel component diagnosis or service. Disconnect and isolate the negative battery (ground) cable, then wait two minutes for the airbag system capacitor to discharge before performing further diagnosis or service. This is the only sure way to disable the airbag system. Failure to follow these instructions may result in accidental airbag deployment and possible serious or fatal injury.

NOTE:

See SYSTEM WIRING DIAGRAMS for circuit descriptions and diagrams. Wiring Information includes wiring diagrams, proper wire and connector repair procedures, further details on wire harness routing and retention, as well as pin-out and location views for the various wire harness connectors, splices and grounds.

Prior to replacing the Positive Temperature Coefficient (PTC) heater unit, check for any Diagnostic Trouble Codes (DTCs) related to the heating and A/C system, Powertrain Control Module (PCM) and Body Control Module (BCM). Repair as necessary. Also, initiate the Actuator Calibration function to verify that the concern is not a heating and A/C system calibration issue. Refer to STANDARD PROCEDURE .

Disconnect and isolate the negative battery cable.
Disconnect the wire harness connector from the PTC heater unit. Refer to UNIT, HEATER, REMOVAL .
Using an ohmmeter, check for continuity between all of the PTC heater unit terminals. In each case there should be continuity. If OK, repair the wire harness circuits between the PTC heater unit and the PCM and the BCM. If not OK, replace the PTC heater unit.