Pinpoint Test I: A Single Climate Controlled Seat is Inoperative - Front
Seats
Pinpoint Test I: A Single Climate Controlled Seat is Inoperative - Front
Normal Operation
Climate controlled seat button commands are communicated from the Front Controls Interface Module (FCIM) over the Medium Speed Controller Area Network (MS-CAN) to the HVAC module and then to the Dual Climate Controlled Seat Module (DCSM). Upon receiving a command, the mode status (high, medium, low or off) is communicated from the DCSM (Dual Climate Controlled Seat Module) to the HVAC module and then to the FCIM (Front Controls Interface Module) which commands the indicators on or off. The climate controlled seat system can only operate if all 3 modules are communicating correctly on the Controller Area Network (CAN).
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- FCIM (Front Controls Interface Module)
- HVAC module
- DCSM (Dual Climate Controlled Seat Module)
PINPOINT TEST I : A SINGLE CLIMATE CONTROLLED SEAT IS INOPERATIVE - FRONT
NOTICE: When taking measurements at Dual Climate Controlled Seat Module (DCSM) harness connectors, do not insert the electrical probes into the female connector pins. Inserting the probes into connector pins can cause intermittent or open electrical connections after reassembly resulting in Diagnostic Trouble Codes (DTCs) and system failure. Touching the tip of these connector pins is recommended instead.
I1 VERIFY CLIMATE CONTROLLED SEAT BLOWER OPERATION
- Ignition OFF.
- Remove the driver and front passenger cushion Thermo-Electric Device (TED) filters to verify blower operation.
- Turn the filter to the left (counterclockwise) and remove.
- Start the engine.
- Operate climate controlled seat buttons while verifying both blowers operate.
Are all climate controlled seats inoperative?
Yes
GO to Symptom Chart to diagnose all climate controlled seats are inoperative. Symptom Related Diagnostic Procedures
No
If only one blower operates, GO to I2.
I2 VERIFY CLIMATE CONTROLLED SEAT INDICATOR ILLUMINATION
- Verify system indicator illumination on the affected seat.
Do any climate controlled seat indicators illuminate or flash and then turn off on the affected seat?
Yes
GO to I3.
No
GO to I4.
I3 CHECK THE DCSM (Dual Climate Controlled Seat Module) FOR DTCs
- Enter the following diagnostic mode on the scan tool: Self Test- DCSM (Dual Climate Controlled Seat Module).
Are any DTCs present?
Yes
GO to the Dual Climate Controlled Seat Module (DCSM) DTC Chart. Seats
No
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 HVAC module connector pins. REPEAT the self-test. CHECK the system for normal operation.
If no intermittent concerns are found, CARRY OUT the Component Test - Thermo-Electric Device (TED) Cooling Performance for both seats. REPEAT the self-test. Component Tests and General Diagnostics
I4 MONITOR THE FCIM (Front Controls Interface Module) PIDs AND CHECK THE INPUTS
- Enter the following diagnostic mode on the scan tool: DataLogger- FCIM (Front Controls Interface Module)- PIDs.
- Driver Cooled Seat (CC_SW_D_CL_S)
- Driver Heated Seat (CC_SW_D_HSEATS)
- Passenger Cooled Seat (CC_SW_P_CL_S)
- Passenger Heated Seat (CC_SW_P_HSEATS)
- Monitor the PIDs while pushing the climate controlled seat switch buttons.
Do the PID values agree with the switch positions?
Yes
GO to I5.
No
INSTALL a new FCIM (Front Controls Interface Module). TEST the system for normal operation.
I5 CHECK THE HVAC MODULE FOR DTCs
- Enter the following diagnostic mode on the scan tool: Self Test- HVAC Module.
Are any DTCs retrieved?
Yes
REFER to Body Control Systems.
No
GO to I6.
I6 CHECK THE DCSM (Dual Climate Controlled Seat Module) USING ACTIVE COMMANDS
- Enter the following diagnostic mode on the scan tool: DataLogger- DCSM (Dual Climate Controlled Seat Module)- PIDs.Driver Seat
- Seat cushion thermal electric device temperature (CSHTEMP)
- Seat back thermal electric device temperature (BK_TEMP)
- Climate-controlled seat heat command (TED_HEAT_D)
Front Passenger Seat
- Passenger Cushion Thermal Electric Device (TED) Temperature (PCSHTMP)
- Passenger Back TED Temperature (PBKTMP)
- Passenger TED Heat Mode (TED_HEAT_P)
- NOTE: The DCSM (Dual Climate Controlled Seat Module) 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 active commands while monitoring the appropriate PIDs.
- When the command is in process, the TED (Thermo-Electric Device) temperature PIDs on the affected seat being commanded 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 fan movement.
Do the PID states or cushion blower movement indicate climate controlled seat operation?
Yes
INSTALL a new HVAC module. TEST the system for normal operation.
No
INSTALL a new DCSM (Dual Climate Controlled Seat Module). REFER to Dual Climate Controlled Seat Module (DCSM) . CLEAR the DTCs. REPEAT the self-test.