Pinpoint Test M: The Heated Seats are Inoperative - Both Front Seats
Seats
Pinpoint Tests
Pinpoint Test M: The Heated Seats are Inoperative - Both Front Seats
Refer to Wiring Diagram Set 119, Climate Controlled Seats for schematic and connector information. Diagrams By Number
Normal Operation
The heated seat module is supplied with 2 battery voltage inputs (one for the driver seat and one for the passenger seat), a single ignition voltage input and a single ground circuit. If equipped with navigation and the heated seat buttons on the Front Controls Interface Module (FCIM) are pressed, the FCIM sends a request message to the HVAC module which controls the heated seats by supplying a momentary ground to the heated seat module. If not equipped with navigation, the HVAC module controls the heated seats by supplying a momentary ground to the heated seat module when a heated seat button on the HVAC is pressed.
The heated seat module monitors the temperature sensor in each seat cushion's heater mat and if the shared return circuit becomes open, the heated seat module will disable both seats.
This pinpoint test is intended to diagnose the following:
- Fuse(s)
- Wiring, terminals or connectors
- Heated seat module
- HVAC module
- FCIM
PINPOINT TEST M: THE HEATED SEATS ARE INOPERATIVE - BOTH FRONT SEATS
NOTE: If a seat equipped with a seat mounted side air bag is being repaired, the Supplemental Restraint System (SRS) must be depowered. Refer to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
NOTE: The air bag warning lamp illuminates when the Restraints Control Module (RCM) fuse is removed and the ignition switch is ON. This is normal operation and does not indicate an SRS fault.
NOTE: The SRS must be fully operational and free of faults before releasing the vehicle to the customer.
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M1 CHECK THE HEATED SEAT OPERATION
- Start the engine.
- Verify both heated seats do not heat.
- Are both heated seats inoperative?
Yes
If equipped with navigation, GO to M2.
If not equipped with navigation, GO to M4.
No
For driver seat inoperative, GO to Pinpoint Test N. Pinpoint Test N: The Heated Seat is Inoperative - Driver
For passenger seat inoperative, GO to Pinpoint Test O. Pinpoint Test O: The Heated Seat is Inoperative - Front Passenger
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M2 CHECK THE FCIM FOR DTCs
- Enter the following diagnostic mode on the scan tool: Self Test - FCIM.
- Retrieve and record all FCIM DTCs.
- Are any FCIM DTCs retrieved?
Yes
For all FCIM DTCs, REFER to the DTC Chart in Information and Entertainment Systems Front Controls Interface Module (FCIM).
No
GO to M3.
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M3 MONITOR THE FCIM PIDs
- Enter the following diagnostic mode on the scan tool: DataLogger - FCIM.
- Monitor the following FCIM PIDs while individually pressing the driver and passenger heated seat buttons.
- Driver Heated Seat (CC_SW_D_HSEATS)
- Passenger Heated Seat (CC_SW_P_HSEATS)
- Do the PID statuses agree with the button settings?
Yes
GO to M4.
No
INSTALL a new FCIM. REFER to Information and Entertainment Systems Front Controls Interface Module (FCIM). TEST the system for normal operation.
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M4 CHECK THE HVAC MODULE FOR DTCs
- Enter the following diagnostic mode on the scan tool: Self Test - HVAC module.
- Retrieve and record all HVAC module DTCs.
- Are any HVAC module DTCs retrieved?
Yes
REFER to the HVAC Module DTC Chart. HVAC Module DTC Chart
No
If equipped with navigation, GO to M5.
If not equipped with navigation, GO to M6.
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M5 CHECK THE OTHER 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.
- Operate the other HVAC systems (rear defrost, blower fan, temperature control, etc.) and verify the operation.
- Do the other HVAC systems function correctly?
Yes
GO to M6.
No
REFER to Climate Control System - General Information and Diagnostics Testing and Inspection to diagnose the HVAC module.
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M6 MONITOR THE HVAC MODULE HEATED SEAT PIDs
- Enter the following diagnostic mode on the scan tool: DataLogger - HVAC module.
- NOTE: The PID data will quickly flicker on and off. Watch closely when pressing the switch buttons.
- Monitor the following HVAC module PIDs while individually pressing the driver and passenger heated seat buttons.
- Left Seat Heater (ST_HEAT_LT)
- Right Seat Heater (ST_HEAT_RT)
- Do the PID statuses agree with the button settings?
Yes
GO to M7.
No
INSTALL a new HVAC module. REFER to Climate Control Service and Repair. TEST the system for normal operation.
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M7 CHECK FOR VOLTAGE TO THE HEATED SEAT MODULE
- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Passenger Seat Side Air Bag Module C339.
- Disconnect: Heated Seat Module C359B.
- WARNING: Make sure no one is in the vehicle and there is nothing blocking or placed in front of any air bag module when the battery is connected. Failure to follow these instructions may result in serious personal injury in the event of an accidental deployment.
- Connect the battery ground cable. Refer to Battery, Mounting and Cables Battery Disconnect.
- Ignition ON.
- Measure the voltage between:
- heated seat module C359B-1, circuit CBX01 (GN/RD), harness side and ground.
- heated seat module C359B-2, circuit SBX06 (GY/RD), harness side and ground.
- Are the voltages greater than 10 volts?
Yes
GO to M8.
No
VERIFY Body Control Module (BCM) fuse 33 (10A) and Battery Junction Box (BJB) fuse 69 (30A) are OK. If OK, REPAIR the circuit(s). If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. TEST the system for normal operation. Diagrams By Number
DISCONNECT the battery ground cable.
CONNECT passenger seat side air bag module C339.
REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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M8 CHECK THE HEATED SEAT MODULE GROUND CIRCUIT FOR AN OPEN
- Ignition OFF.
- Measure the resistance between heated seat module C359B-5, circuit GD903 (BK/WH), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
GO to M9.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable.
CONNECT passenger seat side air bag module C339.
REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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M9 CHECK THE HEATED SEAT MODULE SENSOR RETURN CIRCUIT FOR AN OPEN
- Disconnect: Heated Seat Module C359A.
- Disconnect: Passenger Seat Cushion Heater C334.
- Measure the resistance between heated seat module C359A-12, circuit RHS05 (YE/VT), harness side and passenger seat cushion heater C334-3, circuit RHS05 (YE/VT), harness side.
- Is the resistance less than 5 ohms?
Yes
INSTALL a new heated seat module. REFER to Heated Seat Module - Front Heated Seat Module - Front. TEST the system for normal operation.
DISCONNECT the battery ground cable.
CONNECT passenger seat side air bag module C339.
REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable.
CONNECT passenger seat side air bag module C339.
REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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