Pinpoint Test L: A Single Climate Controlled Seat is Inoperative - Switch Indicators May Or May Not Illuminate
Seats
Pinpoint Tests
Pinpoint Test L: A Single Climate Controlled Seat is Inoperative - Switch Indicators May Or May Not Illuminate
Refer to Wiring Diagram Set 119, Climate Controlled Seats for schematic and connector information. Diagrams By Number
Normal Operation
The Dual Climate Controlled Seat Module (DCSM) is supplied voltage 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 buttons on the touchscreen interface. When commanding a heat or cool mode operation in this manner, it only operates in 15 second intervals. Both DCSM voltage supply circuits are spliced together inside 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 is disabled by the DCSM.
The DCSM receives all control commands over the Controller Area Network (CAN) communication circuits from the HVAC module which contains the climate controlled seat switches. The climate controlled seat system can only operate if both the HVAC module and DCSM are communicating correctly on the CAN circuits.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Medium Speed Controller Area Network (MS-CAN) fault
- HVAC module
- DCSM
PINPOINT TEST L: A SINGLE CLIMATE CONTROLLED SEAT IS INOPERATIVE - SWITCH INDICATORS MAY OR MAY NOT ILLUMINATE
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L1 CHECK THE OPERATION OF BOTH CLIMATE CONTROLLED SEATS AND VERIFY THE SYMPTOM
- Check the operation of both climate controlled seats and verify the symptom.
- Is only a single climate controlled seat inoperative?
Yes
GO to L2.
No
If both seats are inoperative, GO to Symptom Chart. Symptom Related Diagnostic Procedures
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L2 CHECK FOR DCSM DTCs
- Enter the following diagnostic mode on the scan tool: Self Test - DCSM.
- Were any DTCs retrieved during the self-tests?
Yes
GO to the Dual Climate Controlled Seat Module (DCSM) DTC Chart. Dual Climate Controlled Seat Module (DCSM) DTC Chart
No
GO to L3.
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L3 CHECK OPERATION OF THE DCSM USING PIDs
NOTE: The purpose of this step is to verify the DCSM is able to receive and process inbound command messages from the communication bus and demonstrate if the DCSM is operational. This indicates the HVAC module may not be sending the commands correctly.
- Enter the following diagnostic mode on the scan tool: DataLogger - DCSM.
Driver Seat
- Seat cushion Thermo-Electric Device (TED) temperature (CSHTEMP)
- Seat back TED temperature (BK_TEMP)
- Climate-controlled seat heat command (TED_HEAT_D)
Front Passenger Seat
- Passenger Cushion TED Temperature (PCSHTMP)
- Passenger Back TED Temperature (PBKTMP)
- Passenger TED Heat Mode (TED_HEAT_P)
- NOTE: The DCSM active commands TED_HEAT_D (driver seat) and TED_HEAT_P (passenger seat) are limited to 15 seconds in the ON state, then turn OFF.
- Operate the affected climate controlled seat using the active command while monitoring the appropriate PIDs for that seat.
- When the command is in process the TED temperature PIDs on the affected seat should momentarily increase. If no temperature increase is noted, remove the cushion blower filter and repeat the active command while physically monitoring the cushion blower for movement.
- Do the PID states or cushion blower movement indicate climate controlled seat operation when using the active command?
Yes
GO to L4.
No
INSTALL a new DCSM. REFER to Dual Climate Controlled Seat Module (DCSM) Dual Climate Controlled Seat Module (DCSM). CLEAR the DTCs. TEST the system for normal operation.
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L4 USE THE CLIMATE CONTROLLED SEAT SWITCH AND MONITOR THE DCSM PID FOR A RESPONSE
- Enter the following diagnostic mode on the scan tool: DataLogger - DCSM.
- Driver State Seat Mode (DCCSMOD) (driver seat)
- Passenger State Seat Mode (PCCSMOD) (passenger seat)
- Start the engine.
- NOTE: Operation of the climate controlled seats repeatedly ON and OFF or repeatedly switching between heat and cool modes may cause DCSM DTCs to set, disabling one or both seat systems and may require DTCs to be cleared before seat operation may continue. It is recommended to allow time between modes for seat temperatures to return toward ambient temperatures before continuing.
- Attempt to operate the affected climate controlled seat in all modes using the appropriate switch while monitoring the DCSM PID DCCSMOD (driver seat) or PCCSMOD (passenger seat).
- Do all the PID states match the climate controlled seat settings selected?
Yes
If the fault is intermittent, CHECK for causes of the intermittent fault. INSPECT the connectors, terminals and wiring. ATTEMPT to recreate the fault by flexing the wire harness and operating the system. CHECK the electrical connectors for corrosion, poor pin contact or pushed-out pins. REPAIR any intermittent concerns found and TIGHTEN any loose DCSM connector pins. CLEAR the DTCs. REPEAT the self-test.
No
If equipped with navigation, INSTALL a new Front Controls Interface Module (FCIM), REFER to Information and Entertainment Systems Front Controls Interface Module (FCIM). If not equipped with navigation, INSTALL a new HVAC module. REFER to Climate Control Service and Repair. CLEAR the DTCs. TEST the system for normal operation.
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