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Pinpoint Test T: A Single Climate Controlled Seat Is Inoperative - Switch Indicators May or May Not Illuminate




Seats

Pinpoint Tests

Pinpoint Test T: A Single Climate Controlled Seat is 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 seats are independently controlled by the Dual Climate Controlled Seat Module (DCSM) mounted to the bottom of the passenger seat cushion. The climate controlled seat system only operates with the engine running, however, if using a scan tool to command the DCSM, diagnostic testing can be carried out with the ignition Key ON Engine OFF (KOEO). The system receives voltage from Battery Junction Box (BJB) fuse 12 (30A) supplying battery voltage on circuit SBB12 (GN/RD) into DCSM C3305a pin F. The system also receives voltage from BJB fuse 11 (30A) supplying battery voltage on circuit SBB11 (BU/RD) into DCSM C3305a pin E. If voltage is disconnected from either pin E or F of DCSM C3305a with the voltage connection remaining on the other circuit, both seats will remain operational because the voltage supply circuits are connected internally in the DCSM. However, if a fault occurs setting a DTC specific to either climate controlled seat, only the affected seat will be disabled by the module and the other will remain operational.

The seat cushion is equipped with a Thermo-Electric Device (TED) assembly that includes a seat blower (fan motor, serviced as an assembly with the TED). Similarly, the seat backrest is also equipped with its own TED assembly with blower. Cabin air is drawn through the blower and distributed to each of the TED modules located in the seat cushion and backrest. The TEDs then heat or cool the air. The air is then directed into the foam pad and manifold where it is distributed along the surface of the cushion and backrest of the seat. Once the system is activated, the DCSM uses a set of flexible algorithms to control the heating/cooling modes and the blower speed dependant on the HVAC module seat switch settings.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Medium-speed controller area network (MS-CAN)
- HVAC module
- DCSM



PINPOINT TEST T: A SINGLE CLIMATE CONTROLLED SEAT IS INOPERATIVE - SWITCH INDICATORS MAY OR MAY NOT ILLUMINATE

NOTE: The air bag warning indicator illuminates when the correct Restraints Control Module (RCM) fuse is removed and the ignition switch is ON.

NOTE: The Supplemental Restraint System (SRS) must be fully operational and free of faults before releasing the vehicle to the customer.

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T1 CHECK OPERATION OF BOTH CLIMATE CONTROLLED SEATS AND VERIFY THE SYMPTOM


- Check the operation of both climate controlled seats and verify the symptom.
- Does the climate controlled seat system operate on either seat?

Yes
GO to T2.

No
If both seats are inoperative Go To Pinpoint Test S. Pinpoint Test S: All Climate Controlled Seats Are Inoperative

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T2 CHECK FOR DCSM AND HVAC MODULE DTCs


- Enter the following diagnostic mode on the scan tool: Self Test - DCSM.
- Enter the following diagnostic mode on the scan tool: Self Test - HVAC Module.
- Were any DTCs retrieved?

Yes
For DCSM DTCs, GO to the Dual Climate Controlled Seat Module (DCSM) DTC Chart.

For HVAC module DTCs, REFER to Heating and Air Conditioning to diagnose the HVAC module fault.

No
GO to T3.

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T3 CHECK DCSM USING ACTIVE COMMANDS


NOTE: The purpose of this step is to verify the DCSM is able to receive and process inbound command messages from the communication bus and demonstrate if the DCSM is operational. This indicates the HVAC module may not be sending the commands correctly.

- Enter the following diagnostic mode on the scan tool: DataLogger - DCSM - 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 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 active commands while monitoring the appropriate PIDs.
- 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 fan movement.
- Do the PID states or cushion blower movement indicate climate controlled seat operation?

Yes
GO to T4.

No
INSTALL a new DCSM and CARRY OUT Programmable Module Installation (PMI). REFER to Dual Climate Controlled Seat Module (DCSM) Dual Climate Controlled Seat Module (DCSM). REPEAT the self-test. CLEAR the DTCs.

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T4 USE THE CLIMATE CONTROLLED SEAT SWITCH AND MONITOR THE DCSM PID FOR A RESPONSE


- Enter the following diagnostic mode on the scan tool: DataLogger - DCSM - PIDs.
- 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 DCSM 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.
- Operate the affected climate controlled seat in all modes using the appropriate switch while monitoring the DCSM PID DCCSMOD (driver seat) or PCCSMOD (passenger seat).
- Do PID states agree with the switch settings?

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 connector pins. REPEAT the self-test. CLEAR the
DTCs.

No
INSTALL a new HVAC module. REFER to Heating and Air Conditioning. REPEAT the self-test. CLEAR the DTCs.

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