Pinpoint Test L: A Single Climate Controlled Seat is Inoperative - Switch Indicators May or May Not Illuminate
Seats
Pinpoint Test L: A Single Climate Controlled Seat is Inoperative - Switch Indicators May or May Not Illuminate
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 (Dual Climate Controlled Seat Module) 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. When commanding a heat or cool mode operation with the scan tool, the system will only operate in 15-second intervals. Both voltage supply circuits are spliced together internal to the DCSM (Dual Climate Controlled Seat Module), so if one circuit becomes open, both seats can still be operated. However, if a fault occurs specific to either climate controlled seat, only the affected seat will be disabled by the DCSM (Dual Climate Controlled Seat Module).
When equipped with navigation, 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 DCSM (Dual Climate Controlled Seat Module). Upon receiving a command, the DCSM (Dual Climate Controlled Seat Module) then communicates indicator illumination commands back to the HVAC module which then commands the FCIM (Front Controls Interface Module) to turn the indicators on or off. No direct connection exists between the FCIM (Front Controls Interface Module), HVAC module and DCSM (Dual Climate Controlled Seat Module). The climate controlled seat system can only operate if all 3 modules are communicating correctly on the Controller Area Network (CAN).
When not equipped with navigation, climate controlled seat button commands are communicated from the HVAC module over the MS-CAN (Medium Speed Controller Area Network) to the DCSM (Dual Climate Controlled Seat Module). Upon receiving a command, the DCSM (Dual Climate Controlled Seat Module) then communicates indicator illumination commands back to the HVAC module to turn the indicators on or off. No direct connection exists between the HVAC module and DCSM (Dual Climate Controlled Seat Module). The climate controlled seat system can only operate if both modules are communicating correctly on the CAN (Controller Area Network).
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- MS-CAN (Medium Speed Controller Area Network) fault
- FCIM (Front Controls Interface Module)
- HVAC module
- DCSM (Dual Climate Controlled Seat Module)
PINPOINT TEST L : A SINGLE CLIMATE CONTROLLED SEAT IS INOPERATIVE - SWITCH INDICATORS MAY OR MAY NOT ILLUMINATE
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.
L1 VERIFY CLIMATE CONTROLLED SEAT BLOWER OPERATION
- Ignition OFF.
- Remove the driver and front passenger cushion TED (Thermo-Electric Device) 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 both blowers operate, GO to L3.
If only one blower operates, GO to L2.
L2 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 L3.
No
For vehicles with navigation, GO to L4.
For vehicles without navigation, GO to L5.
L3 RETRIEVE DCSM (Dual Climate Controlled Seat Module) DTCs
- Enter the following diagnostic mode on the scan tool: Self Test- DCSM (Dual Climate Controlled Seat Module).
Are any DTCs retrieved?
Yes
GO to the Dual Climate Controlled Seat Module (DCSM) DTC Chart. Seats
No
GO to L6.
L4 MONITOR THE FCIM (Front Controls Interface Module) PIDs AND CHECK 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 L6.
No
INSTALL a new FCIM (Front Controls Interface Module). TEST the system for normal operation.
L5 MONITOR THE HVAC MODULE PIDs AND CHECK INPUTS
- Enter the following diagnostic mode on the scan tool: DataLogger- HVAC 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 L6.
No
INSTALL a new HVAC module. TEST the system for normal operation.
L6 CHECK OPERATION OF 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). 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 while monitoring the appropriate PIDs.
- When the command is in process, the TED (Thermo-Electric Device) temperature PIDs 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?
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 (Dual Climate Controlled Seat Module) connector pins. CLEAR the DTCs. REPEAT the self-test.
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.