Pinpoint Test L: A Single Climate Controlled Seat Is Inoperative - Rear
Seats
Pinpoint Test L: A Single Climate Controlled Seat is Inoperative - Rear
Refer to Wiring Diagram Set 119, Climate Controlled Seats for schematic and connector information. Diagrams By Number
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 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, 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.
The PCSM-2 receives all control commands over the Controller Area Network (CAN) communication circuits from the RHVAC module which contains the climate controlled seat switches. The climate controlled seat system can only operate if both the RHVAC module and PCSM-2 are communicating correctly on the CAN circuits.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Medium Speed Controller Area Network (MS-CAN) fault
- RHVAC module
- PCSM-2
PINPOINT TEST L: A SINGLE CLIMATE CONTROLLED SEAT IS INOPERATIVE - REAR
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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
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L2 CHECK FOR PCSM-2 AND RHVAC MODULE DTCs
- Enter the following diagnostic mode on the scan tool: Self Test - PCSM-2.
- Enter the following diagnostic mode on the scan tool: Self Test - RHVAC module.
- Were any DTCs retrieved during the self tests?
Yes
For PCSM-2 DTCs, GO to the Passenger Climate Controlled Seat Module - 2 (PCSM-2) DTC Chart. Passenger Climate Controlled Seat Module - 2 (PCSM-2) DTC Chart
For RHVAC module DTCs, REFER to Climate Control System - General Information and Diagnostics Testing and Inspection to diagnose the RHVAC module fault.
No
GO to L3.
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L3 CHECK OPERATION OF THE PCSM-2 USING PIDs
NOTE: The purpose of this step is to verify the PCSM-2 is able to receive and process inbound command messages from the communication bus and demonstrate if the PCSM-2 is operational. This indicates the RHVAC module may not be sending the commands correctly.
- Enter the following diagnostic mode on the scan tool: DataLogger - PCSM-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 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 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. REFER to Passenger Climate - Controlled Seat Module (PCSM-2) Passenger Climate - Controlled Seat Module (PCSM-2). REPEAT the self-test. CLEAR the DTCs.
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L4 USE THE CLIMATE CONTROLLED SEAT SWITCH AND MONITOR THE PCSM-2 PID FOR A RESPONSE
- Enter the following diagnostic mode on the scan tool: DataLogger - PCSM-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 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 module while monitoring the PCSM-2 PID DCCSMOD (driver seat) or PCCSMOD (passenger seat).
- Do all the PID states match the climate controlled seat settings selected on the RHVAC 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 connector pins. REPEAT the self-test. CLEAR the DTCs.
No
INSTALL a new RHVAC module. REFER to Climate Control Rear Heating Ventilation Air Conditioning (RHVAC) Module. REPEAT the self-test. CLEAR the DTCs.
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