Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Diagnostic Test
- TEST FOR INTERMITTENT CONDITION NOTE:
Make sure the battery is fully charged and the charging system is operating properly before proceeding.
- Turn the ignition on.
- Using a scan tool, record and erase Diagnostic Trouble Codes (DTCs).
- Turn the ignition off.
- Start the engine and let it run.
- Turn the Heated Seat on and operate in all modes.
- Using a scan tool, read DTCs.
Is the DTC active?
Yes
- Go To 2
No
- The conditions that caused this code to set are not present at this time. Verify seat harness is routed correctly. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors. Look for chafed, pierced, pinched, or partially broken wires and broken, bent, pushed out, spread, corroded, or contaminated terminals. Attempt to reproduce condition by adjusting the front seat.
- Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
- CHECK FOR OPEN RIGHT REAR SEAT CUSHION HEATER ELEMENT
- Turn the ignition off.
- Disconnect the Right Rear Seat Cushion Heater harness connector.NOTE:
Check connectors. Clean and repair as necessary.
- Measure the resistance between the (P178) Right Rear Seat Heater Control circuit and the (Z919) Ground circuit at the Right Rear Seat Cushion Heater Connector (seat side).
Is the resistance above 4.8 Ohms?
Yes
- Replace the Rear Seat Cushion Heater Element in accordance with the Service Information. Refer to PAD, HEATER, REMOVAL .
- Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
No
- Go To 3
- CHECK (P178) RIGHT REAR SEAT HEATER CONTROL CIRCUIT FOR AN OPEN IN BODY HARNESS
Courtesy of CHRYSLER GROUP, LLC
- Disconnect the HSM C3 harness connector.NOTE:
Check connectors. Clean and repair as necessary.
- Measure the resistance of the (P178) Right Rear Seat Heater Control circuit between the HSM C3 harness connector and the Right Rear Seat Cushion Heater harness connector (harness side).
Is the resistance below 5.0 Ohms?
Yes
- Go To 4
No
- Repair the (P178) Right Rear Seat Heater Control circuit for an open.
- Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
- Disconnect the HSM C3 harness connector.
- CHECK (Z919) GROUND CIRCUIT FOR AN OPEN
- Measure the resistance of the (Z919) Ground circuit between ground and the Right Rear Seat Cushion Heater harness connector (harness side).
Is the resistance below 5.0 Ohms?
Yes
- Replace the Heated Seat Module (HSM) in accordance with the Service Information. Refer to REMOVAL .
- Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
No
- Repair the (Z919) Ground circuit for an open.
- Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
- Measure the resistance of the (Z919) Ground circuit between ground and the Right Rear Seat Cushion Heater harness connector (harness side).
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.