Pinpoint Test Q: The Heated Seat Is Inoperative/Does Not Operate Correctly - Left Rear
Seats
Pinpoint Test Q: The Heated Seat is Inoperative/Does Not Operate Correctly - Left Rear
Refer to Wiring Diagram Set 119, Climate Controlled Seats for schematic and connector information Electrical Diagrams.
Normal Operation
When the LH or RH rear heated seat control switch is activated with the ignition ON, a ground signal is supplied to he heated seat module to command the system in hi heat mode or low heat mode. When commanded ON, voltage is supplied to the heated seat switch from the heated seat module to illuminate the switch indicator. The heated seat module also supplies voltage to the LH or RH rear seat cushion and backrest heater mats, which are connected in series. 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 remains on, heating the seat and maintaining temperature until switched off or the ignition is turned OFF.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Heater mat
- Heated seat module
- Heated seat switch
PINPOINT TEST Q : THE HEATED SEAT IS INOPERATIVE/DOES NOT OPERATE CORRECTLY - LEFT REAR
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.
Q1 CHECK FOR VOLTAGE TO THE HEATED SEAT MODULE
- Disconnect: Heated Seat Module C3162A.
- Measure the voltage between heated seat module C3162A-1, circuit SBB30 (BN/RD), harness side and ground.
Is the voltage greater than 10 volts?
Yes
GO to Q2.
No
REPAIR the circuit. TEST the system for normal operation.
Q2 CHECK THE HEATER ELEMENT POWER CIRCUIT FOR AN OPEN OR SHORT TO GROUND
- Disconnect: Left Rear Cushion Heater Mat C3167.
- Measure the resistance between:
- left rear seat cushion heater mat C3167-1, circuit CHS39 (GN/BU), harness side and ground.
- left rear seat cushion heater mat C3167-1, circuit CHS39 (GN/BU), harness side and heated seat module C3162A-4, circuit CHS39 (GN/BU), harness side.
Is the resistance greater than 10,000 ohms between the left rear seat cushion heater mat and ground; and less than 5 ohms between the left rear seat cushion heater mat and the heated seat module?
Yes
GO to Q3.
No
REPAIR the circuit. TEST the system for normal operation.
Q3 CHECK THE HEATED SEAT TEMPERATURE SENSOR CIRCUIT FOR AN OPEN OR SHORT TO GROUND
- Disconnect: Heated Seat Module C3162B.
- Measure the resistance between:
- left rear seat cushion heater mat C3167-2, circuit VHS42 (GN), harness side and ground.
- left rear seat cushion heater mat C3167-2, circuit VHS42 (GN), harness side and heated seat module C3162B-3, circuit VHS42 (GN), harness side.
Is the resistance greater than 10,000 ohms between the left rear seat cushion heater mat and ground and less than 5 ohms between the left rear seat cushion heater mat and the heated seat module?
Yes
GO to Q4.
No
REPAIR the circuit. TEST the system for normal operation.
Q4 CHECK THE SENSOR RETURN CIRCUIT FOR AN OPEN OR SHORT TO GROUND
- Measure the resistance between:
- left rear seat cushion heater mat C3167-3, circuit RHS41 (GN/BN), harness side and ground.
- left rear seat cushion heater mat C3167-3, circuit RHS41 (GN/BN), harness side and heated seat module C3162B-12, circuit RHS41 (GN/BN), harness side.
Is the resistance greater than 10,000 ohms between the left rear seat cushion heater mat and ground and less than 5 ohms between the left rear seat cushion heater mat and the heated seat module?
Yes
GO to Q5.
No
REPAIR the circuit. TEST the system for normal operation.
Q5 CHECK THE HEATED SEAT CIRCUITS FOR A SHORT TO VOLTAGE
- Ignition ON.
- Measure the voltage between the following left rear seat cushion heater mat C3167 pins, harness side and ground:
Connector - Pin Circuit C3167-1 CHS39 (GN/BU) C3167-2 VHS42 (GN) C3167-3 RHS41 (GN/BN)
Is voltage present on any circuits?
Yes
REPAIR the affected circuit. TEST the system for normal operation.
No
GO to Q6.
Q6 CHECK THE HEATER ELEMENT GROUND CIRCUIT FOR AN OPEN
- Ignition OFF.
- Measure the resistance between left rear seat cushion heater mat C3167-4, circuit GD126 (BK/WH), harness side and ground.
Is the resistance less than 5 ohms?
Yes
GO to Q7.
No
REPAIR the circuit. TEST the system for normal operation.
Q7 CHECK CUSHION HEATED SEAT MAT FOR AN OPEN AND A SHORT TO GROUND
- Ignition OFF.
- Disconnect: Left Rear Seat Cushion Heater Mat to Left Rear Seat Backrest Heater Mat Connector.
- Measure the resistance between:
- left rear seat cushion heater mat C3167 pin 1, component side and ground.
- left rear seat cushion heater mat C3167 pin 1, component side and left rear seat cushion heater mat to left rear seat backrest heater mat connector pin 1, cushion side.
Is the resistance greater than 10,000 ohms between the left rear seat cushion heater mat and ground; and between 1.2 and 2.2 ohms between the left rear seat cushion heater mat and left rear seat backrest heater mat?
Yes
GO to Q8.
No
INSTALL a new cushion heater mat. TEST the system for normal operation.
Q8 CHECK BACKREST HEATED SEAT MAT FOR AN OPEN AND A SHORT TO GROUND
- Measure the resistance between:
- left rear seat backrest heater mat connector pin 2, component side and ground.
- left rear seat backrest heater mat connector pin 1 and pin 2, component side.
Is the resistance greater than 10,000 ohms between the left rear seat backrest heater mat and ground; and between 1.2 and 2.2 ohms between the left rear seat backrest heater mat pins?
Yes
GO to Q9.
No
INSTALL a new backrest heater mat. TEST the system for normal operation.
Q9 CHECK CIRCUIT BETWEEN BACKREST AND CUSHION HEATER MAT
- Measure the resistance between left rear seat cushion heater mat C3167 pin 4, component side and left rear seat cushion heater mat to left rear seat backrest heater mat connector pin 2, cushion side.
Is the resistance less than 5 ohms?
Yes
GO to Q10.
No
INSTALL a new cushion heater mat. TEST the system for normal operation.
Q10 CHECK THE HEATED SEAT TEMPERATURE SENSOR AND CIRCUITS FOR AN OPEN AND A SHORT TO GROUND
- Measure the resistance between:
- left rear seat cushion heater mat C3167 pin 2 and pin 3, component side.
- left rear seat cushion heater mat C3167 pin 2, component side and ground.
Is the resistance less than 170,000 ohms and greater than 725 ohms between left rear seat cushion heater mat pins; and greater than 10,000 ohms between left rear seat cushion heater mat and ground?
Yes
GO to Q11.
No
INSTALL a new cushion heater mat. TEST the system for normal operation.
Q11 CHECK THE HEATED SWITCH CIRCUITS FOR A SHORT TO VOLTAGE
- Disconnect: Left Rear Heated Seat Switch C722.
- Ignition ON.
- Measure the voltage between:
- heated seat module C3162B-2, circuit CHS46 (YE/GN), harness side and ground.
- heated seat module C3162B-1, circuit CHS47 (VT/GN), harness side and ground.
Is voltage present on either circuit?
Yes
REPAIR the circuit. TEST the system for normal operation.
No
GO to Q12.
Q12 CHECK THE HEATED SWITCH CIRCUITS FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between:
- heated seat module C3162B-2, circuit CHS46 (YE/GN), harness side and ground.
- heated seat module C3162B-1, circuit CHS47 (VT/GN), harness side and ground.
Are the resistances greater than 10,000 ohms?
Yes
GO to Q13.
No
REPAIR the circuit. TEST the system for normal operation.
Q13 CHECK BETWEEN THE HEATED SWITCH CIRCUITS FOR A SHORT
- Measure the resistance between heated seat module C3162B-2, circuit CHS46 (YE/GN), harness side and heated seat module C3162B-1, circuit CHS47 (VT/GN), harness side.
Are the resistances greater than 10,000 ohms?
Yes
GO to Q14.
No
REPAIR the circuits. TEST the system for normal operation.
Q14 CHECK THE HEATED SWITCH CIRCUITS FOR AN OPEN
- Measure the resistance between:
- heated seat module C3162B-2, circuit CHS46 (YE/GN), harness side and left rear heated seat switch C722-6, circuit CHS46 (YE/GN), harness side.
- heated seat module C3162B-1, circuit CHS47 (VT/GN), harness side and left rear heated seat switch C722-2, circuit CHS47 (VT/GN), harness side.
Are the resistances less than 5 ohms?
Yes
GO to Q15.
No
REPAIR the circuit. TEST the system for normal operation.
Q15 CHECK THE HEATED SEAT SWITCH GROUND CIRCUIT FOR AN OPEN
- Measure the resistance between left rear heated seat switch C722-1, circuit GD126 (BK/WH), harness side and ground.
Is the resistance less than 5 ohms?
Yes
GO to Q16.
No
REPAIR the circuit. TEST the system for normal operation.
Q16 CHECK THE RIGHT REAR HEATED SEAT SWITCH
- Connect the right rear heated seat switch to the left rear heated seat switch connector.
- Ignition ON.
- Check the left rear heated seat operation.
Does the left rear heated seat operate correctly?
Yes
INSTALL a new heated seat switch. REFER to Heated Seat Switch - Rear Seat . TEST the system for normal operation.
No
INSTALL a new heated seat module. REFER to Heated Seat Module - Rear Seat . TEST the system for normal operation.