Pinpoint Test Q: The Heated Seats are Inoperative - Front

Seats

Pinpoint Tests

Pinpoint Test Q: The Heated Seats are Inoperative - Front

Refer to Wiring Diagram Set 119, Climate Controlled Seats for schematic and connector information. Diagrams By Number

Normal Operation

The heated seat module receives ignition voltage on circuit CBP35 (YE/GY), battery voltage on circuit SBB16 (VT/RD) and is supplied ground on circuit GD133 (BK). When ignition switched voltage is supplied and the driver or passenger heated seat button on the HVAC module is pressed, a momentary ground signal is sent to the heated seat module to command the system ON or OFF. Upon receiving a signal, the heated seat module will decrease one setting (the sequence is hi, lo, OFF, hi, etc.). The heated seat module supplies voltage to the cushion and backrest heater mats, which are connected in series and operate together. A separate ground to the heater mats is provided on the backrest heater mat. Temperature is maintained by the heated seat module using a sensor contained within the cushion heater mat. The heated seat module supplies a reference voltage to the temperature sensor and monitors the return signal from the temperature sensor for controlling current flow to the heater mats. The heated seat module is designed to remain ON, heating the seat and maintaining temperature until switched OFF from the HVAC module or the ignition switch is turned OFF.

This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Heated seat module



PINPOINT TEST Q: THE HEATED SEATS ARE INOPERATIVE - FRONT

WARNING: Never install heated seat parts not intended for use on this vehicle. Parts released for other model years or vehicle lines are not compatible even if they appear visually and physically similar. Installing incorrect parts will result in heated seat system performance outside design specification. Failure to follow this instruction may result in serious personal injury.

NOTE: The air bag warning indicator illuminates when the correct Restraints Control Module (RCM) fuse is removed and the ignition 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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Q1 CHECK FOR VOLTAGE TO THE HEATED SEAT MODULE


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in the General Procedures portion of Restraint Systems.
- Disconnect: Passenger Seat Side Air Bag C327.
- Disconnect: Heated Seat Module C329.
- 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.
- Ignition ON.
- Measure the voltage between:
- heated seat module C329-2, circuit CBP35 (YE/GY), harness side and ground.
- heated seat module C329-1, circuit SBB16 (VT/RD), harness side and ground.




- Are the voltages greater than 10 volts?

Yes
GO to Q2.

No
VERIFY Battery Junction Box (BJB) fuse 16 (30A) and Smart Junction Box (SJB) fuse 35 (10A) are OK. If OK, REPAIR the affected circuit. If not OK, Refer to the Wiring Diagrams to identify 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 C327.

REPOWER the SRS. REFER to Restraint Systems.

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Q2 CHECK THE HEATED SEAT MODULE GROUND


- Ignition OFF.
- Measure the resistance between heated seat module C329-7, circuit GD133 (BK), harness side and ground.




- Is the resistance less than 5 ohms?

Yes
GO to Q3.

No
REPAIR the circuit. TEST the system for normal operation.

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

REPOWER the SRS. REFER to Restraint Systems.

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Q3 CHECK THE SENSOR RETURN CIRCUIT FOR A SHORT TO VOLTAGE


- Ignition ON.
- Measure the voltage between heated seat module C329-13, circuit RHS05 (YE/VT), harness side and ground.




- Is any voltage present?

Yes
REPAIR the circuit. TEST the system for normal operation.

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

REPOWER the SRS. REFER to Restraint Systems.

No
GO to Q4.

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Q4 CHECK THE SENSOR RETURN CIRCUIT FOR A SHORT TO GROUND


- Ignition OFF.
- Measure the resistance between heated seat module C329-13, circuit RHS05 (YE/VT), harness side and ground.




- Is the resistance greater than 10,000 ohms?

Yes
GO to Q5.

No
REPAIR the circuit. TEST the system for normal operation.

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

REPOWER the SRS. REFER to Restraint Systems.

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Q5 CHECK THE SENSOR RETURN CIRCUIT FOR AN OPEN


- Disconnect: Passenger Heated Seat C3284.
- Measure the resistance between heated seat module C329-13, circuit RHS05 (YE/VT), harness side and passenger heated seat C3284-3, circuit RHS05 (YE/VT), harness side.




- Is the resistance less than 5 ohms?

Yes
GO to Q6.

No
REPAIR the circuit. TEST the system for normal operation.

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

REPOWER the SRS. REFER to Restraint Systems.

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Q6 CHECK THE HEATED SEAT GROUND


- Measure the resistance between heated seat C3284-4, circuit GD145 (BK/BU), harness side and ground.




- 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 C327.

REPOWER the SRS. REFER to Restraint Systems.

No
REPAIR the circuit. TEST the system for normal operation.

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

CONNECT driver seat side air bag module C328.

REPOWER the SRS. REFER to Restraint Systems.

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