Pinpoint Test S: The Heated Seat is Inoperative - Left Rear
Seats
Pinpoint Tests
Pinpoint Test S: The Heated Seat is Inoperative - Left Rear
Refer to Wiring Diagram Set 119, Climate Controlled Seats for schematic and connector information. Diagrams By Number
Normal Operation
The Battery Junction Box (BJB) supplies battery voltage to the heated seat module on circuit SBP18 (YE/RD), ignition voltage is supplied from the Smart Junction Box (SJB) on circuit CPB35 (YE/GY) and ground on circuit GD143 (BK/VT). When the heated seat control switch is pressed, a ground signal is sent to the heated seat module to command the system ON or OFF in HI heat mode or LOW heat mode. When commanded ON, a ground signal is supplied from the heated seat switch to the heated seat module on either circuit CHS46 (YE/GN) (HI heat mode) or circuit CHS47 (VT/GN) (LO heat mode) illuminating the switch indicator. The heated seat module also supplies voltage to the cushion and backrest heater mats on circuit CHS39 (GN/BU) and ground to the heater mats on circuit GD150 (BK/WH). 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 VHS42 (GN) and monitors the temperature sensor for adjusting the current flow to the heater mats. 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 switch
- Heated seat module
PINPOINT TEST S: THE HEATED SEAT IS INOPERATIVE - LEFT REAR
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S1 CHECK THE HEATED SEAT OPERATION
- Ignition ON.
- Operate the left rear heated seat switch.
- Does the seat operate in either setting?
Yes
If only the LOW setting operates, GO to S15.
If only the HIGH setting operates, GO to S16.
No
GO to S2.
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S2 CHECK THE HEATED SEAT SWITCH INPUT
- Disconnect: Heated Seat Module C3054A.
- Measure the resistance between heated seat module C3054A-2, circuit CHS46 (YE/GN), harness side and ground while pressing the left rear heated seat switch to high.
- Is the resistance less than 30 ohms when the heated seat switch is pressed and greater than 10,000 ohms when the heated seat switch is not pressed?
Yes
GO to S4.
No
GO to S3.
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S3 CHECK THE HEATED SEAT SWITCH GROUND CIRCUIT FOR AN OPEN
- Disconnect: Left Rear Heated Seat Switch C3181.
- Measure the resistance between left rear heated seat switch C3181-1, circuit GD143 (BK/VT), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
GO to S17.
No
REPAIR the circuit. TEST the system for normal operation.
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S4 CHECK FOR VOLTAGE TO THE HEATED SEAT MODULE
- Disconnect: Heated Seat Module C3054B.
- Measure the voltage between heated seat module C3054B-1, circuit SBP18 (YE/RD, harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to S5.
No
REPAIR the circuit. TEST the system for normal operation.
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S5 CHECK THE HEATER MATS RESISTANCE AND HEATER CIRCUITS FOR AN OPEN
- Measure the resistance between heated seat module C3054B-4, circuit CHS39 (GN/BU), harness side and ground.
- Is the resistance between 3 and 5 ohms?
Yes
GO to S11.
No
GO to S6.
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S6 CHECK THE HEATER MATS GROUND CIRCUIT FOR AN OPEN
- Disconnect: Left Rear Backrest Heater Mat C3360.
- Measure the resistance between left rear backrest heater mat C3360-2, circuit GD150 (BK/WH), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
GO to S7.
No
REPAIR the circuit. TEST the system for normal operation.
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S7 CHECK THE SWITCH INPUT CIRCUIT FOR AN OPEN OR SHORT TO GROUND
- Disconnect: Left Rear Seat Cushion C3361.
- Measure the resistance between:
- heated seat module C3054B-4, circuit CHS39 (GN/BU), harness side and left rear seat cushion heater mat C3361-1, circuit CHS39 (GN/BU), harness side.
- heated seat module C3054B-4, circuit CHS39 (GN/BU), harness side and ground.
- Is the resistance less than 5 ohms between C3054B-4 and C3361-1, and greater than 10,000 ohms between C3054B-4 and ground?
Yes
GO to S8.
No
REPAIR the circuit. TEST the system for normal operation.
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S8 CHECK CUSHION HEATER MAT FOR AN OPEN
- Measure the resistance between left rear heated seat cushion C3361 pins 1 and pin 4, component side.
- Is the resistance between 0.7 and 1.5 ohms?
Yes
GO to S9.
No
INSTALL a new rear seat cushion heater mat. REFER to Seat Cushion Heater Mat Seat Cushion Heater Mat. TEST the system for normal operation.
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S9 CHECK THE CIRCUIT BETWEEN THE CUSHION AND BACKREST HEATER MATS FOR AN OPEN OR A SHORT TO GROUND
- Measure the resistance between:
- left rear seat cushion heater mat C3361-4, circuit CHS40 (GY/VT), harness side and left rear seat backrest heater mat C3360-1, circuit CHS40 (GY/VT), harness side.
- left rear seat cushion heater mat C3361-4, circuit CHS40 (GY/VT), harness side and ground.
- Is the resistance less than 5 ohms between C3361-4 and C3361-1, and greater than 10,000 ohms between C3361-4 and ground?
Yes
GO to S10.
No
REPAIR the circuit. TEST the system for normal operation.
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S10 CHECK THE BACKREST HEATER MAT FOR AN OPEN
- Measure the resistance between left rear backrest heater mat C3360 pins 1 and 2, component side.
- Is the resistance between 0.7 and 1.5 ohms?
Yes
GO to S11.
No
INSTALL a new rear seat backrest heater mat. REFER to Seat Backrest Heater Mat Seat Backrest Heater Mat. TEST the system for normal operation.
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S11 CHECK THE TEMPERATURE SENSOR INPUT CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition ON.
- Measure the voltage between heated seat module C3054A-3, circuit VHS42 (GN), harness side and ground.
- Is any voltage present?
Yes
REPAIR the circuit. GO to S14 to check the temperature sensor for damage. If temperature sensor is OK, TEST the system for normal operation.
No
GO to S12.
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S12 CHECK THE TEMPERATURE SENSOR INPUT CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between heated seat module C3054A-3, circuit VHS42 (GN), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to S13.
No
REPAIR circuit VHS42 (GN). TEST the system for normal operation.
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S13 CHECK THE TEMPERATURE SENSOR CIRCUITS FOR AN OPEN OR SHORT TO GROUND
- Connect: Left Rear Seat Cushion C3361 (if previously disconnected).
- Measure the resistance between:
- heated seat module C3054A-3, circuit VHS42 (GN), harness side and C3054A-12, circuit RHS41 (GN/BN), harness side.
- heated seat module C3054A-3, circuit VHS42 (GN), harness side and ground.
- Is the resistance greater than 300 and less than 300,000 ohms between C3054A-3 and C3054A-12 and greater than 10,000 ohms between C3054A-12 and ground?
Yes
INSTALL a new heated seat module. REFER to Heated Seat Module - Second Row Heated Seat Module - Second Row. TEST the system for normal operation.
No
GO to S14.
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S14 CHECK THE TEMPERATURE SENSOR FOR AN OPEN
- Disconnect: Left Rear Seat Cushion C3361.
- Measure the resistance between left rear heated seat cushion C3361 pins 2 and 3, component side.
- Is the resistance between 8,000 ohms and 15,000 ohms?
Yes
REPAIR circuit RHS41 (GN/BU) or VHS42 (GN). TEST the system for normal operation.
No
INSTALL a new rear seat cushion heater mat. REFER to Seat Cushion Heater Mat Seat Cushion Heater Mat. TEST the system for normal operation.
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S15 CHECK THE HEATED SEAT SWITCH HIGH CIRCUIT FOR AN OPEN OR SHORT TO GROUND
- Disconnect: Heated Seat Switch C3181.
- Measure the resistance between:
- heated seat module C3054A-2, circuit CHS46 (YE/GN), harness side and left rear heated seat switch C3181-6, circuit CHS46 (YE/GN), harness side.
- heated seat module C3054A-2, circuit CHS46 (YE/GN), harness side and ground.
- Is the resistance less than 5 ohms between the heated seat module and the heated seat switch and greater than 10,000 ohms between the heated seat module and ground?
Yes
GO to S17.
No
REPAIR the circuit. TEST the system for normal operation.
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S16 CHECK THE HEATED SEAT SWITCH LOW CIRCUIT FOR AN OPEN OR SHORT TO GROUND
- Disconnect: Heated Seat Switch C3181.
- Measure the resistance between:
- heated seat module C3054A-1, circuit CHS47 (VT/GN), harness side and left rear heated seat switch C3181-2, circuit CHS47 (VT/GN), harness side.
- heated seat module C3054A-1, circuit CHS47 (YE/GN), harness side and ground.
- Is the resistance less than 5 ohms between the heated seat module and the heated seat switch and greater than 10,000 ohms between the heated seat module and ground?
Yes
GO to S17.
No
REPAIR the circuit. TEST the system for normal operation.
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S17 CHECK THE REAR HEATED SEAT SWITCH
- Disconnect: Heated Seat Switch C3181.
- Measure the resistance between rear heated seat switch pins, component side, while pressing the indicated switch buttons and compare the results to the table.
- Is the heated seat switch OK?
Yes
INSTALL a new heated seat module. REFER to Heated Seat Module - Second Row Heated Seat Module - Second Row. TEST the system for normal operation.
No
INSTALL a new rear heated seat switch. REFER to Heated Seat Switch - Second Row Heated Seat Switch - Second Row.
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