Pinpoint Test R: The Heated Seat is Inoperative/Does Not Operate Correctly - Driver
Seats
Pinpoint Tests
Pinpoint Test R: The Heated Seat is Inoperative/Does Not Operate Correctly - Driver
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 heated seat button on the HVAC module is pressed, a momentary ground signal is sent to the heated seat module on circuit CHS29 (WH/BU) 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 on circuit CHS02 (YE/BU). Ground to the heater mats is provided on circuit GD145 (BK/BU). The cushion and backrest heater mats are connected in series and operate together. 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 on circuit RHS05 (YE/VT) and monitors the signal from the temperature sensor on circuit VHS26 (VT) 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
- Heater mat
- Heated seat module
- HVAC module
PINPOINT TEST R: THE HEATED SEAT IS INOPERATIVE/DOES NOT OPERATE CORRECTLY - DRIVER
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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R1 CHECK CIRCUIT SBB16 (VT/RD) 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: Driver Seat Side Air Bag C328.
- 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.
- Measure the voltage between heated seat module C329-1, circuit SBB16 (VT/RD), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to R2.
No
VERIFY Battery Junction Box (BJB) fuse 16 (30A) is OK. If OK, REPAIR the 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.
CONNECT driver seat side air bag module C328.
REPOWER the SRS. REFER to Restraint Systems.
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R2 CHECK CIRCUIT CHS02 (YE/BU) FOR AN OPEN AND A SHORT TO GROUND
- Disconnect: Driver Cushion Heater Mat C3283.
- Measure the resistance between:
- driver seat cushion heater mat C3283-1, circuit CHS02 (YE/BU), harness side and ground.
- driver seat cushion heater mat C3283-1, circuit CHS02 (YE/BU), harness side and heated seat module C329-9, circuit CHS02 (YE/BU), harness side.
- Is the resistance greater than 10,000 ohms between the driver seat cushion heater mat and ground; and less than 5 ohms between the driver seat cushion heater mat and the heated seat module?
Yes
GO to R3.
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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R3 CHECK CIRCUIT VHS26 (VT) FOR AN OPEN AND A SHORT TO GROUND
- Measure the resistance between:
- driver seat cushion heater mat C3283-2, circuit VHS26 (VT), harness side and ground.
- driver seat cushion heater mat C3283-2, circuit VHS26 (VT), harness side and heated seat module C329-10, circuit VHS26 (VT), harness side.
- Is the resistance greater than 10,000 ohms between the driver seat cushion heater mat and ground and less than 5 ohms between the driver seat cushion heater mat and the heated seat module?
Yes
GO to R4.
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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R4 CHECK CIRCUIT RHS05 (YE/VT) FOR AN OPEN AND A SHORT TO GROUND
- Measure the resistance between:
- driver seat cushion heater mat C3283-3, circuit RHS05 (YE/VT), harness side and ground.
- driver seat cushion heater mat C3283-3, circuit RHS05 (YE/VT), harness side and heated seat module C329-13, circuit RHS05 (YE/VT), harness side.
- Is the resistance greater than 10,000 ohms between the driver seat cushion heater mat and ground and less than 5 ohms between the driver seat cushion heater mat and the heated seat module?
Yes
GO to R5.
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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R5 CHECK CIRCUITS CHS02 (YE/BU), VHS26 (VT) AND RHS05 (YE/VT) FOR A SHORT TO VOLTAGE
- Ignition ON.
- Measure the voltage between the following driver seat cushion heater mat C3283 pins, harness side and ground:
- Is voltage present on any circuits?
Yes
REPAIR the affected 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.
No
GO to R6.
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R6 CHECK CIRCUIT GD145 (BK/BU) FOR AN OPEN
- Ignition OFF.
- Measure the resistance between driver seat cushion heater mat C3283-4, circuit GD145 (BK/BU), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
GO to R7.
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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R7 CHECK CUSHION AND BACKREST HEATER MAT AND SENSOR FOR A SHORT TO VOLTAGE
- Ignition ON.
- Measure the voltage between:
- driver seat cushion heater mat C3283 pin 1, component side and ground.
- driver seat cushion heater mat C3283 pin 2, component side and ground.
- Is voltage present on either circuit?
Yes
REPAIR the circuit. INSTALL a new affected cushion or backrest heater mat. 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.
No
GO to R8.
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R8 CHECK CUSHION HEATED SEAT MAT FOR AN OPEN AND A SHORT TO GROUND
- Ignition OFF.
- Disconnect: Driver Seat Cushion Heater Mat to Driver Seat Backrest Heater Mat Connector.
- Measure the resistance between:
- driver seat cushion heater mat C3283 pin 1, component side and ground.
- driver seat cushion heater mat C3283 pin 1, component side and driver seat cushion heater mat to driver seat backrest heater mat connector pin 1, cushion side.
- Is the resistance greater than 10,000 ohms between the driver seat cushion heater mat and ground; and between 1.2 and 2.2 ohms between the driver seat cushion heater mat to driver seat backrest heater mat?
Yes
GO to R9.
No
INSTALL a new cushion heater mat. 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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R9 CHECK BACKREST HEATED SEAT MAT FOR AN OPEN AND A SHORT TO GROUND
- Measure the resistance between:
- driver seat backrest heater mat connector pin 2, component side and ground.
- driver seat backrest heater mat connector pin 1 and pin 2, component side.
- Is the resistance greater than 10,000 ohms between the driver seat backrest heater mat and ground; and between 1.2 and 2.2 ohms between the driver seat backrest heater mat pins?
Yes
GO to R10.
No
INSTALL a new cushion heater mat. 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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R10 CHECK CIRCUIT BETWEEN BACKREST AND CUSHION HEATER MAT
- Measure the resistance between driver seat cushion heater mat C3283 pin 4, component side and driver seat cushion heater mat to driver seat backrest heater mat connector pin 2, cushion side.
- Is the resistance less than 5 ohms?
Yes
GO to R11.
No
INSTALL a new seat cushion heater mat. 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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R11 CHECK THE HEATED SEAT TEMPERATURE SENSOR AND CIRCUITS FOR AN OPEN AND A SHORT TO GROUND
- Measure the resistance between:
- driver seat cushion heater mat C3283 pin 2 and pin 3, component side.
- driver seat cushion heater mat C3283 pin 2, component side and ground.
- Is the resistance less than 170,000 ohms and greater than 725 ohms between driver seat cushion heater mat pins; and greater than 10,000 ohms between driver seat cushion heater mat and ground?
Yes
GO to R12.
No
INSTALL a new seat cushion heater mat. 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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R12 CHECK CIRCUIT CHS29 (WH/BU) FOR A SHORT TO VOLTAGE
- Disconnect: HVAC Module C228b.
- Ignition ON.
- Measure the voltage between heated seat module C329-12, circuit CHS29 (WH/BU), 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.
CONNECT driver seat side air bag module C328.
REPOWER the SRS. REFER to Restraint Systems.
No
GO to R13.
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R13 CHECK CIRCUIT CHS29 (WH/BU) FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between heated seat module C329-12, circuit CHS29 (WH/BU), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to R14.
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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R14 CHECK CIRCUIT CHS29 (WH/BU) FOR AN OPEN
- Measure the resistance between heated seat module C329-12, circuit CHS29 (WH/BU), harness side and HVAC module C228b-6, circuit CHS29 (WH/BU), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to R15.
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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R15 CHECK THE HVAC MODULE OUTPUT
- Connect: HVAC Module C228b.
- Connect: Heated Seat Module C329.
- Ignition ON.
- NOTE: The following measurement must be taken by back-probing the heated seat module C329.
- NOTE: The voltage on circuit CHS29 (WH/BU) should drop momentarily when the driver heated seat control button is pressed.
- Measure the voltage between heated seat module C329-12, circuit CHS29 (WH/BU), harness side and ground by back-probing heated seat module connector. Press the driver heated seat control button on the HVAC module and note the voltage.
- Is the voltage greater than 10 volts before pressing the driver heated seat control button, then momentarily drops when the heated seat control button is pressed?
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.
CONNECT driver seat side air bag module C328.
REPOWER the SRS. REFER to Restraint Systems.
No
If the voltage is greater than 10 volts but did not drop when the driver heated seat button was pressed, INSTALL a new HVAC module. TEST the system for normal operation.
If the voltage is less than 10 volts, 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.
CONNECT driver seat side air bag module C328.
REPOWER the SRS. REFER to Restraint Systems.
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