Pinpoint Test Q: The Heated Seat Is Inoperative - Passenger
Seats
Pinpoint Tests
Pinpoint Test Q: The Heated Seat is Inoperative - Passenger
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 passenger heated seat button on the HVAC module is pressed, a momentary ground signal is sent to the heated seat module on circuit CHS30 (GN/YE) 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 CHS07 (GY/BU). The cushion and backrest heater mats are connected in series and ground is supplied to the backrest heater mat on circuit GD139 (BK/YE). 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 VHS27 (WH/OG) 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:
- Wiring, terminals or connectors
- Heater mat
- Heated seat module
- HVAC module
PINPOINT TEST Q: THE HEATED SEAT IS INOPERATIVE - PASSENGER
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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Q1 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: 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-3, circuit SBB11 (BU/RD) harness side and ground.
- Is voltage greater than 10 volts?
Yes
GO to Q2.
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 passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
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Q2 CHECK HEATER MAT GROUND CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: Passenger Seat Backrest Heater Mat C335.
- Measure resistance between heated seat module C335-2, circuit GD139 (BK/YE), harness side and ground.
- Is 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 C313. REPOWER the SRS. REFER to Air Bag Systems.
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Q3 CHECK HEATED SEAT TEMPERATURE SENSOR CIRCUIT VHS27 (WH/OG) FOR A SHORT TO VOLTAGE
- Disconnect: Heated Seat Module C3304a.
- Disconnect: Passenger Seat Cushion Heater Mat C334.
- Ignition ON.
- Measure voltage between heated seat module C3304a-9, circuit VHS27 (WH/OG), harness side and ground.
- Is any voltage present?
Yes
REPAIR the circuit. GO to Q6 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.
Seat Cushion Cover - Front Seat Cushion Cover - Front.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
No
GO to Q4.
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Q4 CHECK HEATED SEAT TEMPERATURE SENSOR CIRCUIT VHS26 (VT) FOR AN OPEN AND SHORT TO GROUND
- Ignition OFF.
- Measure resistance between:
- heated seat module C3304a-9, circuit VHS27 (WH/OG), harness side and seat cushion heater mat C334-3, circuit VHS27 (WH/OG), harness side.
- heated seat module C3304a-9, circuit VHS27 (WH/OG), harness side and ground.
- Is resistance less than 5 ohms between C3304a-9 and C334-3, and greater than 10,000 ohms between C3304a-9 and ground?
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 C313. REPOWER the SRS. REFER to Air Bag Systems.
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Q5 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 passenger seat cushion heater mat C334-4, circuit RHS05 (YE/VT), harness side.
- Is 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 C313. REPOWER the SRS. REFER to Air Bag Systems.
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Q6 CHECK HEATED SEAT TEMPERATURE SENSOR FOR AN OPEN
- Measure the resistance between rear heated seat cushion C334 pin 3 and pin 4 component side.
- Is resistance between 8,000 ohms and 15,000 ohms?
Yes
GO to Q7.
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 passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
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Q7 CHECK PASSENGER SEAT HEATER MATS RESISTANCE AND HEATER CIRCUIT FOR AN OPEN
- Connect: Passenger Seat Backrest Heater Mat C335.
- Connect: Passenger Seat Cushion Heater Mat C334.
- Measure resistance between heated seat module C3304b-6, circuit CHS07 (GY/BU), harness side and ground.
- Is resistance between 2.0 and 4.0 ohms?
Yes
GO to Q12.
No
GO to Q8.
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Q8 CHECK PASSENGER SEAT CUSHION HEATER CIRCUIT CHS07 (GY/BU) FOR AN OPEN AND SHORT TO GROUND
- Disconnect: Passenger Seat Cushion Heater Mat C334.
- Measure resistance between:
- heated seat module C3304b-6, circuit CHS07 (GY/BU), harness side and passenger seat cushion heater mat C334-1, circuit CHS02 (YE/BU), harness side.
- heated seat module C3304b-6, 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 Q9.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
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Q9 CHECK PASSENGER SEAT CUSHION HEATER MAT FOR AN OPEN
- Measure resistance between passenger seat cushion heater mat C334 pins 1 and 2, component side.
- Is resistance between 1.3 and 1.8 ohm?
Yes
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 passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
No
GO to Q10.
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Q10 CHECK FOR AN OPEN AND SHORT TO GROUND BETWEEN CUSHION HEATER MAT AND BACKREST HEATER MAT
- Disconnect: Passenger Seat Backrest Heater Mat C335.
- Measure resistance between:
- seat cushion heater mat C334-2, circuit CHS12 (YE/GN), harness side and seat backrest heater mat C335-1, circuit CHS12 (YE/GN) harness side.
- seat cushion heater mat C334-2, circuit CHS12 (YE/GN), harness side and ground.
- Is resistance less than 0.5 ohm?
Yes
GO to Q11.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
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Q11 CHECK PASSENGER SEAT BACKREST HEATER MAT FOR AN OPEN
- Measure resistance between passenger seat backrest heater mat C335 pins 1 and 2, component side.
- Is resistance between 1.0 and 1.6 ohm?
Yes
REPAIR open circuit GD139 (BK/YE). TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
No
INSTALL a new passenger seat backrest heater mat. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
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Q12 CHECK HEATED SEAT MODULE SWITCH INPUT CIRCUIT FOR SHORT TO VOLTAGE
- Disconnect: HVAC Module C228b.
- Ignition ON.
- Measure voltage between heated seat module C3304a-8, circuit CHS30 (GY/YE), 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 C313. REPOWER the SRS. REFER to Air Bag Systems.
No
GO to Q13.
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Q13 CHECK HEATED SEAT MODULE SWITCH INPUT CIRCUIT FOR AN OPEN
- Ignition OFF.
- Measure resistance between heated seat module C3304a-8, circuit CHS30 (GY/YE), harness side and HVAC module C228b-8, circuit CHS30 (GY/YE), harness side.
- Is resistance less than 5 ohms?
Yes
GO to Q14.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
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Q14 CHECK HEATED SEAT MODULE SWITCH INPUT CIRCUIT FOR A SHORT TO GROUND
- Measure resistance between heated seat module C3304a-8, circuit CHS30 (GY/YE), harness side and ground.
- Is resistance greater than 10,000 ohms?
Yes
GO to Q15.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
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Q15 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 CHS30 (GY/YE) should drop momentarily when the passenger heated seat control button is pressed.
- Measure voltage between passenger heated seat module C3304a-8, circuit CHS30 (GY/YE), harness side and ground by back-probing the heated seat module connector. Press the passenger heated seat button on the HVAC module and note the voltage.
- Is voltage greater than 10 volts before pressing the passenger 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 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 passenger heated seat button was pressed, INSTALL a new HVAC module. REFER to Heating and Air Conditioning. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
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 passenger seat side air bag module C313. REPOWER the SRS. REFER to Air Bag Systems.
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