Diagnostic Test

WARNING: This page is about a different car, the 2017 Jeep Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FOR AN ACTIVE DTC
1. With the scan tool, read Comfort Seat Wheel Module (CSWM)) DTCs and record on the repair order.
2. With the scan tool, erase CSWM DTCs.
3. Turn the ignition off.
4. Start the Engine.
5. Turn the Left Front Heated Seat on.
6. With the scan tool, read CSWM DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - Go To 6
CHECK THE (P187) LEFT FRONT SEAT HEATER CONTROL CIRCUIT FOR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the CSWM C2 harness connector.
3. Disconnect the Left Seat Cushion Heater harness connector.
4. Disconnect the Left Seat Back Heater harness connector.
5. Connect a jumper wire between the (P187) Left Front Seat Heater Control circuit and B(+) in the CSWM C2 harness connector.
6. With a 12-volt test light connected to ground, check the (P187) Left Front Seat Heater Control circuit at the Left Seat Cushion and the Back Heater harness connectors (harness side).
  NOTE:
  The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.
  
  Does the test light illuminate brightly at both connectors?
  
  Yes
  - Go To 3
  No
  - Repair the (P187) Left Front Seat Heater Control circuit for high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE (Z919) GROUND CIRCUIT FOR HIGH RESISTANCE
1. With a 12-volt test light connected to 12 volts, check the (Z919) Ground circuit at the Left Seat Cushion and Back Heater harness connectors (harness side).
  Does the test light illuminate brightly at both connectors?
  
  Yes
  - Go To 4
  No
  - Repair the (Z919) Ground circuit for high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE LEFT SEAT CUSHION HEATER ELEMENT RESISTANCE
1. Measure the resistance between the (P187) Left Front Seat Heater Control circuit and the (Z919) Ground circuit at the Left Seat Cushion Heater connector (component side).
  Is the resistance 5.04 Ohms (± 10%)?
  
  Yes
  - Go To 5
  No
  - Replace the Left Seat Cushion Heater Element in accordance with the Service Information. Refer to PAD, HEATER, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE LEFT SEAT BACK HEATER ELEMENT RESISTANCE
1. Measure the resistance between the (P187) Left Front Seat Heater Control circuit and the (Z919) Ground circuit at the Left Seat Back Heater Element connector (component side).
  Is the resistance 5.13 Ohms (± 10%)?
  
  Yes
  - Replace the Comfort Seat Wheel Module (CSWM) in accordance with the Service Information. Refer to MODULE, COMFORT SEAT AND WHEEL (CSWM), REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Replace the Left Seat Back Heater Element in accordance with the Service Information. Refer to COVER, REAR SEAT BACK, 60%, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE WIRING AND CONNECTORS
1. The conditions necessary to set the DTC are not present at this time.
2. Using the schematics as a guide, inspect the wiring and connectors specific to this circuit. Wiggle the wiring and connectors while checking for shorted and open circuits. Attempt to reproduce the condition by adjusting the seat(s).
3. Check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension. Verify the seat wiring harness is routed correctly to the Comfort Seat Wheel Module (CSWM).
4. Check Service Bulletins for any possible causes that may apply.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Test complete.