Component Tests and General Diagnostics
Thermo-Electric Device (TED) Cooling Performance
Component Test
NOTE: This test is intended to check the cooling mode performance of an operational climate controlled seat backrest or cushion TED (Thermo-Electric Device) 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 DCSM (Dual Climate Controlled Seat Module) PIDs (Parameter Identifications):
- Seat cushion TED (Thermo-Electric Device) temperature (CSHTEMP)
- Seat back TED (Thermo-Electric Device) temperature (BK_TEMP)
- Passenger cushion TED (Thermo-Electric Device) temperature (PCSHTMP)
- Passenger back TED (Thermo-Electric Device) temperature (PBKTMP)
- Driver state seat mode (DCCSMOD)
- Passenger state seat mode (PCCSMOD)
2. Any initial PID (Parameter Identification) 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. REFER to Symptom Chart: Seating - Climate Controlled Seating - 1st Row or REFER to DTC Chart: Dual Climate Controlled Seat Module (DCSM) DTC Chart: Dual Climate Controlled Seat Module (DCSM).
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 thermocouple temperature measuring device to monitor the air inlet temperature.
1. Detach the backrest cover lower J-clips and route the wire harness(es) and manual lumbar cable (if equipped) out of the holes in the backrest cover.
2. On each side, separate the backrest cover clip and hook-and-loop strips.
3. Separate the hook-and-loop strips, invert the backrest cover up and remove the first row hog rings.
4. Separate the hook-and-loop strips, invert the backrest cover up as far as it will go.
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 thermocouple device.
1. 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 (Parameter Identification) temperature and record the value.
1. Monitor the MODE PID (Parameter Identification) and verify the system is operating. If during testing the PID (Parameter Identification) 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.
6. Subtract the cushion TED (Thermo-Electric Device) PID (Parameter Identification) 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 thermocouple device to measure the temperature at the backrest TED (Thermo-Electric Device) filter.
8. Use a scan tool to measure the backrest TED (Thermo-Electric Device) PID (Parameter Identification) temperature and record the value.
1. Monitor the MODE PID (Parameter Identification) and verify the system is operating. If during testing the PID (Parameter Identification) 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.
9. Subtract the backrest TED (Thermo-Electric Device) PID (Parameter Identification) 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 (Dual Climate Controlled Seat Module) self-test and if any DTCs (Diagnostic Trouble Codes) is retrieved, REFER to DTC Chart: Dual Climate Controlled Seat Module (DCSM) DTC Chart: Dual Climate Controlled Seat Module (DCSM). Return to the diagnostic routine.