Pinpoint Test U: All Climate Controlled Seats Are Inoperative - Switch Indicators May or May Not Illuminate
Seats
Pinpoint Test U: All Climate Controlled Seats Are Inoperative - Switch Indicators May or May Not Illuminate
Refer to Wiring Diagram Set 119, Climate Controlled Seats for schematic and connector information. [1][2]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 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 setting a DTC specific to either climate controlled seat, only the affected seat is disabled by the DCSM (Dual Climate Controlled Seat Module).
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).
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- MS-CAN (Medium Speed Controller Area Network)
- FCIM (Front Controls Interface Module)
- HVAC module
- DCSM (Dual Climate Controlled Seat Module)
PINPOINT TEST U : ALL CLIMATE CONTROLLED SEATS ARE 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.
U1 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 filters to the left (counterclockwise) and remove.
- Start the engine.
- Operate climate controlled seat buttons while verifying both blowers operate.
Does either blower operate?
Yes
If only one blower operates, GO to Symptom Chart to diagnose a single climate controlled seat is inoperative. Symptom Related Diagnostic Procedures
If both blowers operate, GO to U5.
No
GO to U2.
U2 VERIFY CLIMATE CONTROLLED SEAT INDICATOR ILLUMINATION
- Ignition OFF.
- Start the engine.
- Verify system indicator illumination.
Does any climate controlled seat indicator illuminate or flash and then turn off?
Yes
GO to U5.
No
GO to U3.
U3 CHECK THE FCIM (Front Controls Interface Module) FOR DTCs
- Ignition In ACC.
- Enter the following diagnostic mode on the scan tool: Self Test- FCIM (Front Controls Interface Module).
Are any DTCs retrieved?
Yes
REFER to the Master DTC Chart in Accessories and Optional Equipment. Accessories and Optional Equipment
No
GO to U4.
U4 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 the Master DTC Chart in Heating and Air Conditioning. Heating and Air Conditioning
No
GO to U6.
U5 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. Dual Climate Controlled Seat Module (DCSM) DTC Chart
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 DCSM (Dual Climate Controlled Seat Module) connector pins.
REPEAT the self-test.
If no intermittent concerns are found, CARRY OUT the Component Test - Thermo-Electric Device (TED) Cooling Performance for both seats. Component Tests and General Diagnostics
U6 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 FCIM (Front Controls Interface Module) PIDs while individually pushing driver and passenger climate controlled seat switch buttons.
Do the PID values agree with the switch positions?
Yes
GO to U7.
No
INSTALL a new FCIM (Front Controls Interface Module). TEST the system for normal operation.
U7 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 HVAC module PIDs while individually pushing driver and passenger climate controlled seat switch buttons.
Do the PID values agree with the switch positions?
Yes
GO to U8.
No
INSTALL a new HVAC module. TEST the system for normal operation.
U8 CHECK 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.
- Seat Cushion Thermal Electric Device Temperature (CSHTEMP)
- Seat Back Thermal Electric Device Temperature (BK_TEMP)
- Climate-controlled Seat Heat Command (TED_HEAT_D)
- 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 climate controlled seats using active commands while monitoring the appropriate PIDs.
- When the command is in process, the TED (Thermo-Electric Device) temperature PIDs on the 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
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.
No
INSTALL a new DCSM (Dual Climate Controlled Seat Module). REFER to Dual Climate Controlled Seat Module (DCSM) . REPEAT the self-test. CLEAR the DTCs.