Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. With the scan tool, read Comfort Rear Seat Module (CRSM) DTCs and record on the repair order.
2. With the scan tool, erase CRSM DTCs.
3. Turn the ignition off for ten seconds.
4. Turn the ignition on.
5. Turn the Rear Left Seat Heater on.
6. With the scan tool, read CRSM 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 AN OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the CRSM C1 connector.
3. Disconnect the Rear Left Seat Heater harness connector(s).
4. Measure the resistance of the (P177) Left Rear Seat Heater Control circuit between the Rear Left Seat Heater connector(s) and the CRSM C1 connector.
  Is the resistance above 2.0 Ohms?
  
  Yes
  - 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 .
  No
  - Go To 3
CHECK THE (Z341) GROUND CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. Using a 12 volt test light connected to 12 volts, check the (Z341) Ground circuit in the Rear Left Seat Heater connector.
  NOTE:
  The test light should illuminate brightly. Compare the brightness to that of a direct connection to the battery.
  
  Does the test light illuminate brightly?
  
  Yes
  - Go To 4
  No
  - Repair the (Z341) Ground circuit for an open or high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE (P177) LEFT REAR SEAT HEATER CONTROL CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition on.
2. Measure the voltage of the (P177) Left Rear Seat Heater Control circuit.
  Is there any voltage present?
  
  Yes
  - Repair the (P177) Left Rear Seat Heater Control circuit for a short to voltage.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 5
CHECK DTCS AFTER REPLACING THE REAR LEFT SEAT HEATER
1. Turn the ignition off.
2. Replace the Rear Left Seat Heater in accordance with the Service Information. Refer to PAD, HEATER, REMOVAL AND INSTALLATION .
3. Turn the ignition on.
4. With the scan tool, erase CRSM DTCs.
5. Turn the ignition off for ten seconds.
6. Turn the ignition on.
7. Turn the Rear Left Seat Heater on.
8. With the scan tool, read CRSM DTCs.
  Did the DTC return?
  
  Yes
  - Go To 6
  No
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  - Test complete.
CHECK RELATED HARNESS CONNECTIONS
1. Turn the ignition off.
2. Check the related component and module power supply and ground circuits.
3. Disconnect all CRSM harness connectors.
4. Disconnect all related in-line harness connections (if equipped).
5. Disconnect the related component harness connectors.
6. 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.
7. Reconnect all harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
8. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
9. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
10. With the scan tool, erase DTCs.
11. Using the recorded information along with the When Monitored and Set Conditions, operate the vehicle within the conditions that set the DTC.
12. With the scan tool, read CRSM DTCs.
  Did the DTC return?
  
  Yes
  - Replace the Comfort Rear Seat Module (CRSM) 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
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  - Test complete.