Positive Temperature Coefficient (PTC) Heater Unit

WARNING: This page is about a different car, the 2016 Jeep Wrangler and 2015 Jeep Wrangler. 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 appropriate SYSTEM WIRING DIAGRAMS article 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 Powertrain Control Module (PCM), Totally Integrated Power Module (TIPM) and the heating and A/C system. Repair as necessary.

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 TIPM. If NOT OK, replace the PTC heater unit.