Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. With the scan tool, read Heated Seat Module (HSM) DTCs and record on the repair order.
2. With the scan tool, erase HSM DTCs.
3. Turn the ignition off.
4. Start the Engine.
5. Turn the Left Rear Heated Seat on and operate in all modes.
6. With the scan tool, read HSM DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - Perform the TESTING FOR AN INTERMITTENT CONDITION procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK THE (P177) LEFT REAR SEAT HEATER CONTROL CIRCUIT FOR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the HSM C3 harness connector.
3. Disconnect the Left Rear Seat Cushion Heater harness connector.
4. Disconnect the Left Rear Seat Back Heater harness connector.
5. Connect a jumper wire between B(+) and the (P177) Left Rear Seat Heater Control circuit at the HSM C3 harness connector.
6. With a 12-volt test light connected to ground, check the (P177) Left Rear Seat Heater Control circuit at the Left Rear Seat Cushion and Left Rear Seat 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 (P177) Left Rear Seat Heater Control circuit(s) for high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK (Z922) GROUND CIRCUIT FOR HIGH RESISTANCE
1. Disconnect the jumper wire.
2. With a 12-volt test light connected to 12 volts, check the (Z922) Ground circuit at each of the Left Rear Seat Cushion Heater and the Left Rear Seat Back Heater harness connectors (harness side).
  Does the test light illuminate brightly at both connectors?
  
  Yes
  - Go To 4
  No
  - Repair the (Z922) Ground circuit(s) for high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK LEFT REAR SEAT CUSHION HEATER ELEMENT RESISTANCE
1. Measure the resistance between the (P177) Left Rear Seat Heater Control circuit and the (Z922) Ground circuit at the Left Rear Seat Cushion Heater component connector.
  Is the resistance between 5.3 and 9.9 Ohms?
  
  Yes
  - Go To 5
  No
  - Replace the Left Rear 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 LEFT REAR SEAT BACK HEATER ELEMENT RESISTANCE
1. Measure the resistance between the (P177) Left Rear Seat Heater Control circuit and the (Z922) Ground circuit at the Left Rear Seat Back Heater component connector.
  Is the resistance between 5.2 and 9.9 Ohms?
  
  Yes
  - Go To 6
  No
  - Replace the Left Rear Seat Back Heater Element in accordance with the Service Information. Refer to PAD, HEATER, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all HSM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
  - Proper connector installation.
  - Damaged connector locks.
  - Corrosion.
  - Other signs of water intrusion.
  - Weather seal damage (if equipped).
  - Bent terminals.
  - Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  - Terminals that have been pushed back into the connector cavity.
  - Check for spread terminals and verify proper terminal tension.
  Repair any conditions that are found.
5. Connect all HSM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Connect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
10. With the scan tool, read HSM DTCs.
  Is the same DTC active?
  
  Yes
  - Replace the Heated Seat Module (HSM) in accordance with the Service Information. Refer to MODULE, HEATED SEAT (HSM), REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Repairing the wiring harness or connections corrected the problem.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .