Pinpoint Test P: The Heated Seat is Inoperative - Driver
Seats
Pinpoint Tests
Pinpoint Test P: The Heated Seat is Inoperative - Driver
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 ignition voltage on circuit CBP19 (BN/WH), battery voltage on circuit SBB11 (BU/RD) and ground on circuit GD139 (BK/YE). When ignition 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 heater mat on circuit CHS02 (YE/BU). The cushion and backrest heater mats are connected in series and ground is supplied to the backrest heater mat on circuit GD126 (BK/WH). Temperature is maintained by the heated seat module using a sensor contained within the cushion heater mat. The heated seat module monitors voltage between temperature sensor circuit VHS26 (VT) and sensor return circuit RHS05 (YE/VT). If the temperature sensor return circuit opens (resistance greater than 300,000 ohms), the heated seat module will disable output voltage to the seat. The seat will remain disabled until the circuit is repaired and the heated seat module is reset by cycling the ignition OFF and ON. The heated seat module is designed to remain ON, heating the seat and maintaining temperature until switched OFF.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Heater mat
- Heated seat module
- HVAC module
PINPOINT TEST P: THE HEATED SEAT IS INOPERATIVE - DRIVER
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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P1 CHECK CIRCUIT SBB11 (BU/RD) FOR VOLTAGE
- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in the General Procedures portion of Air Bag Systems.
- Disconnect: Driver Seat Side Air Bag C327.
- Disconnect: Passenger Seat Side Air Bag Module C313.
- Disconnect: Heated Seat Module C3304b.
- 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 voltage between heated seat module C3304b-1, circuit SBB11 (BU/RD) harness side and ground.
- Is voltage greater than 10 volts?
Yes
GO to P2.
No
VERIFY Battery Junction Box (BJB) fuse 11 (20A) is OK. If OK, REPAIR the circuit. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
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P2 CHECK HEATER MAT GROUND CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: Driver Seat Backrest Heater Mat C365.
- Measure resistance between driver seat cushion heater C365-2, circuit GD126 (BK/WH), harness side and ground.
- Is resistance less than 5 ohms?
Yes
GO to P3.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
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P3 CHECK HEATED SEAT TEMPERATURE SENSOR CIRCUIT VHS26 (VT) FOR A SHORT TO VOLTAGE
- Disconnect: Heated Seat Module C3304a.
- Disconnect: Driver Seat Cushion Heater Mat C364.
- Ignition ON.
- Measure voltage between heated seat module C3304a-3, circuit VHS26 (VT), harness side and ground.
- Is any voltage present?
Yes
REPAIR the circuit. GO to P6 to check the temperature sensor for damage. If OK, TEST the system for normal operation. If not OK, INSTALL a new driver seat cushion heater mat. REFER to Seat Cushion Cover - Front Seat Cushion Cover - Front.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
No
GO to P4.
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P4 CHECK HEATED SEAT TEMPERATURE SENSOR CIRCUIT VHS26 (VT) FOR AN OPEN AND SHORT TO GROUND
- Ignition OFF.
- Measure resistance between:
- heated seat module C3304a-3, circuit VHS26 (VT), harness side and rear seat cushion heater mat C364-3, circuit VHS26 (VT), harness side.
- heated seat module C3304a-3, circuit VHS26 (VT), harness side and ground.
- Is resistance less than 5 ohms between C3304a-3 and C364-3, and greater than 10,000 ohms between C3304a-3 and ground?
Yes
GO to P5.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
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P5 CHECK HEATED SEAT TEMPERATURE SENSOR RETURN CIRCUIT FOR AN OPEN
- Measure the resistance between heated seat module C3304a-12, circuit RHS05 (YE/VT), harness side and driver seat cushion heater mat C364-4, circuit RHS05 (YE/VT), harness side.
- Is resistance less than 5 ohms?
Yes
GO to P6.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
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P6 CHECK HEATED SEAT TEMPERATURE SENSOR FOR AN OPEN
- Measure the resistance between rear heated seat cushionC364 pin 3 and pin 4 component side.
- Is resistance between 8,000 ohms and 15,000 ohms?
Yes
GO to P7.
No
INSTALL a new cushion heater mat. REFER to Seat Cushion Cover - Front Seat Cushion Cover - Front. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
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P7 CHECK DRIVER SEAT HEATER MATS RESISTANCE AND HEATER CIRCUIT FOR AN OPEN
- Connect: Driver Seat Backrest Heater Mat C365.
- Connect: Driver Seat Cushion Heater Mat C364.
- Measure resistance between heated seat module C3304b-4, circuit CHS02 (YE/BU), harness side and ground.
- Is resistance between 2.0 and 4.0 ohms?
Yes
GO to P12.
No
GO to P8.
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P8 CHECK DRIVER SEAT CUSHION HEATER CIRCUIT CHS02 (YE/BU) FOR AN OPEN AND SHORT TO GROUND
- Disconnect: Driver Seat Cushion Heater Mat C364.
- Measure resistance between:
- heated seat module C3304b-4, circuit CHS02 (YE/BU), harness side and driver seat cushion heater mat C364-1, circuit CHS02 (YE/BU), harness side.
- heated seat module C3304b-4, circuit CHS02 (YE/BU), harness side and ground.
- Is resistance less than 5 ohms between heated seat module and cushion heater mat and greater than 10,000 ohms between the heated seat module and ground?
Yes
GO to P9.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
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P9 CHECK DRIVER SEAT CUSHION HEATER MAT FOR AN OPEN
- Measure resistance between driver seat cushion heater mat C364 pins 1 and 2, component side.
- Is resistance between 1.3 and 1.8 ohm?
Yes
GO to P10.
No
INSTALL a new driver seat cushion heater mat. REFER to Seat Cushion Cover - Front Seat Cushion Cover - Front. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
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P10 CHECK FOR AN OPEN AND SHORT TO GROUND BETWEEN CUSHION HEATER MAT AND BACKREST HEATER MAT
- Disconnect: Driver Seat Backrest Heater Mat C365.
- Measure resistance between:
- seat cushion heater mat C364-2, circuit CHS11 (VT/GN), harness side and seat backrest heater mat C365-1, circuit CHS11 (VT/GN) harness side.
- seat cushion heater mat C364-2, circuit CHS11 (VT/GN), harness side and ground.
- Is resistance less than 0.5 ohm?
Yes
GO to P11.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
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P11 CHECK DRIVER SEAT BACKREST HEATER MAT FOR AN OPEN
- Measure resistance between driver seat backrest heater mat C365 pins 1 and 2, component side.
- Is resistance between 1.0 and 1.6 ohm?
Yes
REPAIR open circuit GD126 (BK/WH). TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
No
INSTALL a new driver seat backrest heater mat. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
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P12 CHECK HEATED SEAT MODULE SWITCH INPUT CIRCUIT FOR SHORT TO VOLTAGE
- Disconnect: HVAC Module C228b.
- Ignition ON.
- Measure voltage between heated seat module C3304a-2, 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 driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
No
GO to P13.
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P13 CHECK HEATED SEAT MODULE SWITCH INPUT CIRCUIT FOR AN OPEN
- Ignition OFF.
- Measure resistance between heated seat module C3304a-2, circuit CHS29 (WH/BU), harness side and HVAC module C228b-7, circuit CHS29 (WH/BU), harness side.
- Is resistance less than 5 ohms?
Yes
GO to P14.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
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P14 CHECK HEATED SEAT MODULE SWITCH INPUT CIRCUIT FOR A SHORT TO GROUND
- Measure resistance between heated seat module C3304a-2, circuit CHS29 (WH/BU), harness side and ground.
- Is resistance greater than 10,000 ohms?
Yes
GO to P15.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
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P15 CHECK THE HVAC MODULE OUTPUT
- Connect: HVAC Module C228b.
- Connect: Heated Seat Module C3304a and C3304b.
- Ignition ON.
- NOTE: The following measurement must be taken by back-probing heated seat module C3304a.
- NOTE: Voltage on circuit CHS29 (WH/BU) should drop momentarily when the driver heated seat control button is pressed.
- Measure voltage between heated seat module C3304a-2, circuit CHS29 (WH/BU), harness side and ground by back-probing heated seat module connector. Press the driver heated seat button on the HVAC module and note the voltage.
- Is 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 Heated Seat Module. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
No
If voltage is greater than 10 volts but did not drop when the driver heated seat button was pressed, INSTALL a new HVAC module. REFER to Heating and Air Conditioning. TEST the system for normal operation.
If voltage is less than 10 volts, INSTALL a new heated seat module. REFER to Heated Seat Module Heated Seat Module. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
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