Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. With the scan tool, read DTCs and record on the repair order.
2. Record the Environmental Data.
3. With the scan tool, erase DTCs.
4. Start the engine.
5. Turn the Left Rear Heated Seat on.
6. With the scan tool, read Comfort Seat and Wheel Module (CSWM) DTCs.
  Is the same DTC active?
  
  Yes
  - Go To 2
  No
  - Perform the TESTING FOR AN INTERMITTENT CONDITION procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK THE LEFT REAR SEAT CUSHION HEATER ELEMENT RESISTANCE
1. Turn the ignition off.
2. Disconnect the Left Rear Seat Cushion Heater harness connector.
3. Measure the resistance between the (P177) Left Rear Seat Heater Control circuit and the (Z921) Ground circuit at the Left Rear Seat Cushion Heater component connector.
  NOTE:
  When probing a circuit always use an appropriate back probing tool to prevent any possible damage to the terminals.
  
  Is the resistance between 4.1 and 6.4 Ohms?
  
  Yes
  - Replace the Left Rear Seat Cushion Heater Element in accordance with the Service Information. Refer to PAD, HEATER, REMOVAL AND INSTALLATION .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 3
CHECK (P177) LEFT REAR SEAT HEATER CONTROL CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. Disconnect the CSWM C3 harness connector.
2. Measure the resistance of the (P177) Left Rear Seat Heater Control circuit between the CSWM C3 harness connector and the Left Rear Seat Cushion Heater harness connector (harness side).
  Is the resistance below 1.0 Ohm?
  
  Yes
  - Go To 4
  No
  - Repair the (P177) Left Rear Seat Heater Control circuit for an open or high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK (Z921) GROUND CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. With a 12-volt test light connected to 12 volts, check the (Z921) Ground circuit at the Left Rear Seat Cushion Heater harness connector (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?
  
  Yes
  - Go To 5
  No
  - Repair the (Z921) Ground circuit for an open or high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK RELATED HARNESS CONNECTIONS
1. Turn the ignition off.
2. Disconnect all CSWM harness connectors.
3. Disconnect all related in-line harness connections (if equipped).
4. Disconnect the related component harness connectors.
5. 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.
  - Perform a terminal drag test on each connector terminal to verify proper terminal tension.
  Repair any conditions that are found.
6. Reconnect all CSWM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
9. With the scan tool, erase DTCs.
10. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
11. With the scan tool, read CSWM DTCs.
  Is the same DTC active?
  
  Yes
  - Replace the Comfort Seat Wheel Module (CSWM) in accordance with the Service Information. Refer to MODULE, COMFORT SEAT AND WHEEL (CSWM), REMOVAL AND INSTALLATION .
  - 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 .