Component Tests and General Diagnostics
Seats
Component Test
Component Testing - Thermo-Electric Device (TED) Cooling Performance
NOTE: This test is intended to check the cooling mode performance of an operational climate controlled seat backrest or cushion Thermo-Electric Device (TED) and verify it is cooling inlet air at the TED (Thermo-Electric Device) (ambient cabin air) between 6-8°C (10-14°F).
NOTE: Make sure the vehicle is out of direct sunlight and is in an area with a stable air temperature when testing the climate controlled seat system.
NOTE: For correct temperature measurements, the seat being tested should be occupied.
1. Enter DataLogger and monitor the following Dual Climate Controlled Seat Module (DCSM) PIDs:
- CSHTEMP (Seat cushion thermal electric device temperature)
- BK_TEMP (Seat back thermal electric device temperature)
- PCSHTMP (Passenger Cushion Thermal Electric Device [TED] Temperature)
- PBKTMP (Passenger Back TED Temperature)
- DCCSMOD (Driver State Seat Mode)
- PCCSMOD (Passenger State Seat Mode)
2. Any initial PID value of greater than 205°C (401°F) or less than 2°C (36°F) indicates a system hardware failure. Do not proceed with this test. GO to Symptom Chart or Dual Climate Controlled Seat Module (DCSM) DTC Chart for diagnosis. Symptom Related Diagnostic Procedures Dual Climate Controlled Seat Module (DCSM) DTC Chart
3. NOTE: Typical backrest and cushion TED (Thermo-Electric Device) shown, others similar.
Gain access to the seat backrest and cushion TEDs (Thermo-Electric Devices) and use a suitable thermo-couple temperature measuring device to monitor the air inlet temperature.
- Access the backrest TED (Thermo-Electric Device).
- Release the backrest trim cover J-clips at the sides and bottom.
- Pull out at the bottom and detach the 2 lower hard back panel pin-type retainers.
- Position the backrest trim cover aside.
- Place the temperature probe near each TEDs (Thermo-Electric Devices) air filter.
4. NOTE: The engine must be running to operate the climate controlled seat system and carry out this test.
Operate system in high cool mode and measure the temperature at the cushion TED (Thermo-Electric Device) filter using the thermo-couple device.
- Obtain and record the air inlet temperature at the TED (Thermo-Electric Device).
5. Use a scan tool to measure the cushion TED (Thermo-Electric Device) PID temperature and record the value.
- Monitor the MODE PID and verify the system is operating. If during testing the PID value changes to Blower Only state, the system has entered into recovery mode and voltage to the TEDs (Thermo-Electric Devices) is disabled. If this occurs, the seat has failed the test. Do not continue. Return to the diagnostic routine. Symptom Related Diagnostic Procedures
6. Subtract the cushion TED (Thermo-Electric Device) PID temperature from the cushion air inlet temperature and record the temperature difference value.
7. Continue to operate the system in high cool mode and use the thermo-couple device to measure the temperature at the backrest TED (Thermo-Electric Device) filter.
- Obtain and record the air inlet temperature at the TED (Thermo-Electric Device).
- Secure the temperature probe at the backrest TED (Thermo-Electric Device) air filter and close the backrest trim cover before measuring.
8. Use a scan tool to measure the backrest TED (Thermo-Electric Device) PID temperature and record the value.
- Monitor the MODE PID and verify the system is operating. If during testing the PID value changes to Blower Only state, the system has entered into recovery mode and voltage to the TEDs (Thermo-Electric Devices) is disabled. If this occurs, the seat has failed the test. Do not continue. Return to the diagnostic routine. Symptom Related Diagnostic Procedures
9. Subtract the backrest TED (Thermo-Electric Device) PID temperature from the backrest air inlet temperature and record the value.
10. Compare the cushion and backrest calculated temperature values. Both values should be between 6°-8°C (10.8°-14.4°F) and approximately equal (±1°C [±1.8°F]).
11. If the calculated temperature values are not within these specifications, check the climate controlled seat components for air duct or filter restrictions, blockages, duct or electrical disconnections and for incorrect assembly. Repair as needed. If OK, carry out the DCSM (Dual Climate Controlled Seat Module) self-test and if any DTC is retrieved, go to Dual Climate Controlled Seat Module (DCSM) DTC Chart for diagnostic direction. Return to the diagnostic routine. Dual Climate Controlled Seat Module (DCSM) DTC Chart Symptom Related Diagnostic Procedures