Pinpoint Test L: A Single Climate Controlled Seat is Inoperative - Rear
Seats
Pinpoint Test L: A Single Climate Controlled Seat is Inoperative - Rear
Normal Operation
The Passenger Climate Controlled Seat Module - 2 (PCSM-2) is supplied voltage from Battery Junction Box (BJB) fuse 7 (30A) to C3365A pins E and F, circuit SBB07 (WH/RD). The PCSM-2 (Passenger Climate Controlled Seat Module - 2) is supplied ground from C3365A pin M, circuit GD133 (BK). Both voltage supply circuits are hot at all times but the climate controlled seat system only operates with the engine running. The system can be operated with the ignition ON by using a scan tool to bypass the climate controlled seat switches on the Rear Heating Ventilation Air Conditioning (RHVAC) module and when commanding a heat or cool mode operation in this manner will only operate in 15-second intervals. Both voltage supply circuits are spliced together internal to the PCSM-2 (Passenger Climate Controlled Seat Module - 2), 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 will be disabled by the PCSM-2 (Passenger Climate Controlled Seat Module - 2).
The PCSM-2 (Passenger Climate Controlled Seat Module - 2) receives all control commands over the Controller Area Network (CAN) communication circuits from the RHVAC (Rear Heating Ventilation Air Conditioning) module which contains the climate controlled seat switches. The climate controlled seat system can only operate if both the RHVAC (Rear Heating Ventilation Air Conditioning) module and PCSM-2 (Passenger Climate Controlled Seat Module - 2) are communicating correctly on the CAN (Controller Area Network) circuits.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Medium Speed Controller Area Network (MS-CAN) fault
- RHVAC (Rear Heating Ventilation Air Conditioning) module
- PCSM-2 (Passenger Climate Controlled Seat Module - 2)
PINPOINT TEST L : A SINGLE CLIMATE CONTROLLED SEAT IS INOPERATIVE - REAR
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
L2 CHECK FOR PCSM-2 (Passenger Climate Controlled Seat Module - 2) AND RHVAC (Rear Heating Ventilation Air Conditioning) MODULE DTCs
- Enter the following diagnostic mode on the scan tool: Self Test- PCSM-2 (Passenger Climate Controlled Seat Module - 2).
- Enter the following diagnostic mode on the scan tool: Self Test- RHVAC (Rear Heating Ventilation Air Conditioning) module.
Were any DTCs retrieved during the self tests?
Yes
For PCSM-2 (Passenger Climate Controlled Seat Module - 2) DTCs, GO to the Passenger Climate Controlled Seat Module - 2 (PCSM-2) DTC Chart. Seats
For RHVAC (Rear Heating Ventilation Air Conditioning) module DTCs, REFER to Heating and Air Conditioning to diagnose the RHVAC (Rear Heating Ventilation Air Conditioning) module fault.
No
GO to L3.
L3 CHECK OPERATION OF THE PCSM-2 (Passenger Climate Controlled Seat Module - 2) USING PIDs
NOTE: The purpose of this step is to verify the PCSM-2 (Passenger Climate Controlled Seat Module - 2) is able to receive and process inbound command messages from the communication bus and demonstrate if the PCSM-2 (Passenger Climate Controlled Seat Module - 2) is operational. This indicates the RHVAC (Rear Heating Ventilation Air Conditioning) module may not be sending the commands correctly.
- Enter the following diagnostic mode on the scan tool: DataLogger- PCSM-2 (Passenger Climate Controlled Seat Module - 2). Driver Side Seat
- Seat cushion thermal electric device temperature (CSHTEMP)
- Seat back thermal electric device temperature (BK_TEMP)
- Climate-controlled seat heat command (TED_HEAT_D)
Passenger Side Seat
- Passenger Cushion Thermo-Electric Device (TED) Temperature (PCSHTMP)
- Passenger Back TED Temperature (PBKTMP)
- Passenger TED Heat Mode (TED_HEAT_P)
- NOTE: The PCSM-2 (Passenger Climate Controlled Seat Module - 2) 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 (Thermo-Electric Device) 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 PCSM-2 (Passenger Climate Controlled Seat Module - 2). REFER to Passenger Climate - Controlled Seat Module (PCSM-2) . REPEAT the self-test. CLEAR the DTCs.
L4 USE THE CLIMATE CONTROLLED SEAT SWITCH AND MONITOR THE PCSM-2 (Passenger Climate Controlled Seat Module - 2) PID FOR A RESPONSE
- Enter the following diagnostic mode on the scan tool: DataLogger- PCSM-2 (Passenger Climate Controlled Seat Module - 2).
- 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 PCSM-2 (Passenger Climate Controlled Seat Module - 2) DTCs to set, disabling one or both seat system 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 on the RHVAC (Rear Heating Ventilation Air Conditioning) module while monitoring the PCSM-2 (Passenger Climate Controlled Seat Module - 2) PID DCCSMOD (driver seat) or PCCSMOD (passenger seat).
Do all the PID states match the climate controlled seat settings selected on the RHVAC (Rear Heating Ventilation Air Conditioning) module?
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 PCSM-2 (Passenger Climate Controlled Seat Module - 2) connector pins. REPEAT the self-test. CLEAR the DTCs.
No
INSTALL a new RHVAC (Rear Heating Ventilation Air Conditioning) module. REPEAT the self-test. CLEAR the DTCs.