Pinpoint Test AE: All Climate Controlled Seats Are Inoperative - Switch Indicators May or May Not Illuminate
Seating
Pinpoint Test AE: 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. Diagrams By Number
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 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. 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 AE : 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.
AE1 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 AE5.
No
GO to AE2.
AE2 VERIFY CLIMATE CONTROLLED SEAT INDICATOR ILLUMINATION
- Verify system indicator illumination.
Does any climate controlled seat indicator illuminate or flash and then turn off?
Yes
GO to AE5.
No
GO to AE3.
AE3 CHECK THE FCIM (Front Controls Interface Module) FOR DTCs
- 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 Body Control Systems. Master DTC Index
No
GO to AE4.
AE4 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 Body Control Systems. Master DTC Index
No
For vehicles with navigation, GO to AE6.
For vehicles without navigation, GO to AE7.
AE5 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 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
AE6 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 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
INSTALL a new HVAC module. TEST the system for normal operation.
No
INSTALL a new FCIM (Front Controls Interface Module). TEST the system for normal operation.
AE7 CHECK THE HVAC FUNCTIONS
NOTE: The purpose of this step is to verify the HVAC module is able to receive and process inbound command messages from the communication bus and demonstrate the HVAC module is operational. This indicates the climate controlled seat buttons on the FCIM (Front Controls Interface Module) may not be sending the commands.
- Operate the A/C, heater and defrost using the buttons on the FCIM (Front Controls Interface Module) and check for correct HVAC function.
Does the HVAC system function correctly?
Yes
GO to AE8.
No
REFER to Heating and Air Conditioning to diagnose the HVAC concern.
AE8 MONITOR THE HVAC MODULE PIDs AND CHECK THE 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 AE9.
No
INSTALL a new FCIM (Front Controls Interface Module). TEST the system for normal operation.
AE9 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.
- 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
INSTALL a new FCIM (Front Controls Interface 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.