Component Tests and General Diagnostics

Seats

Component Test

Component Test - 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 (ambient cabin air) between 6-8°C (10-14°F).

NOTE: Make sure the vehicle is out of direct sunlight and 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:
- Seat cushion thermal electric device temperature (CSHTEMP)

- Seat back thermal electric device temperature (BK_TEMP)

- Passenger cushion thermal electric device TED temperature (PCSHTMP)

- Passenger back TED temperature (PBKTMP)

- Driver state seat mode (DCCSMOD)

- Passenger state seat mode (PCCSMOD)

2. Any initial PID value of more 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 shown.

Gain access to the seat cushion and backrest TEDs and use a suitable thermo-couple temperature measuring device to monitor the air inlet temperature.

- Fully raise the seat to access the cushion TED.

- Release the J-clip at the backrest bottom and both J-clips at the backrest side edges to access the backrest TED.

- Place the temperature probe near each TEDs air filter.





4. NOTE: The engine must be running to operate the climate controlled seat system and carry out this test.

Operate the system in high cool mode and measure the temperature at the cushion TED filter using the thermocouple device.

- Obtain and record the air inlet temperature at the TED.
- Secure the temperature probe at the cushion TED air filter before measuring.

5. Use a scan tool to measure the cushion TED 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 is disabled. If this occurs, the seat has failed the test. Do not continue. Return to the diagnostic routine.

6. Subtract the cushion TED 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 filter.
- Obtain and record the air inlet temperature at the TED.
- Secure the temperature probe at the backrest TED air filter and close the backrest cover before measuring.

8. Use a scan tool to measure the backrest TED 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 is disabled. If this occurs, the seat has failed the test. Do not continue. Return to the diagnostic routine.

9. Subtract the backrest TED PID temperature from the backrest air inlet temperature and record the value.

10. Compare the cushion and backrest calculated temperature values. The temperature difference should be between 6 and 8 degrees.

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 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