Pinpoint Test M: A Single Climate Controlled Seat Does Not Operate Correctly - Poor Airflow Or Cooling/Heating Performance
Seats
Pinpoint Tests
Pinpoint Test M: A Single Climate Controlled Seat Does Not Operate Correctly - Poor Airflow or Cooling/Heating Performance
Normal Operation
The Dual Climate Controlled Seat Module (DCSM) is supplied voltage from Battery Junction Box (BJB) fuse 22 (30A) to C3265a pins E and F, circuit CBX01 (GN/RD). The DCSM is supplied ground from C3265a pin M, circuit GD903 (BK/WH). Both voltage supply circuits are hot at all times but the climate controlled seat system only operates with the engine running. The system can be operated with the ignition ON engine OFF by using a scan tool to bypass the climate controlled seat switches on the Front Controls Interface Module (FCIM) (with navigation) or the HVAC module (without navigation). When commanding a heat or cool mode operation in this manner, the system will only operate in 15-second intervals. Both voltage supply circuits are spliced together internal to the DCSM, so if one circuit becomes open, both seats can still be operated. However, if a fault occurs setting a DTC specific to either climate controlled seat, only the affected seat will be disabled by the DCSM and the other seat will remain operational.
When equipped with navigation, the FCIM communicates climate controlled seat commands to the HVAC module using the Medium Speed Controller Area Network (MS-CAN) communication bus. The HVAC module then communicates climate controlled seat commands to the DCSM using the MS-CAN communication bus. No direct connection exists between the FCIM, HVAC module and DCSM for the climate controlled seat switches. The climate controlled seat system can only operate if all 3 modules are communicating correctly on the Controller Area Network (CAN) circuits.
When not equipped with navigation, the HVAC module communicates climate controlled seat commands to the DCSM using the MS-CAN communication bus. No direct connection exists between the DCSM and HVAC module for the climate controlled seat switches. The climate controlled seat system can only operate if both modules are communicating correctly on the CAN circuits.
This pinpoint test is intended to diagnose the following:
- Excessive sunload or extreme cabin temperatures
- Incorrectly installed Thermo-Electric Device (TED)
- Airflow blockage
- Disconnected air duct
PINPOINT TEST M: A SINGLE CLIMATE CONTROLLED SEAT DOES NOT OPERATE CORRECTLY - POOR AIRFLOW OR COOLING/HEATING PERFORMANCE
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M1 CHECK FOR DCSM DTCs
- Enter the following diagnostic mode on the scan tool: Self Test - DCSM.
- Are any DTCs present?
Yes
REFER to Dual Climate Controlled Seat Module (DCSM) DTC Chart. Dual Climate Controlled Seat Module (DCSM) DTC Chart
No
GO to M2.
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M2 CHECK THE TED COOLING PERFORMANCE
- Check the TEDs cooling performance on the affected seat and verify the system is operating correctly. Refer to Component Test - Thermo-Electric Device (TED) Cooling Performance. Component Tests and General Diagnostics
- Did the TEDs pass the component test and the system is operating correctly?
Yes
Extreme cabin temperatures or excessive sunload on the seat may cause the system to enter recovery mode. Occupant size and weight characteristics can also be a factor. If a concern cannot be found or duplicated, RETURN the vehicle to the customer.
No
DISASSEMBLE the seat as necessary to INSPECT the climate controlled seat components in the seat backrest and cushion (TED inlets and outlets, air ducts, filters, and foam pad) for damage, disconnection, restriction or incorrect installation and REPAIR or INSTALL new components as needed. TEST the system for normal operation.
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