Pinpoint Test R: The Heated Seats Are Inoperative - Rear
Seats
Pinpoint Tests
Pinpoint Test R: The Heated Seats are Inoperative - Rear
Refer to Wiring Diagram Set 119, Climate Controlled Seats for schematic and connector information. Diagrams By Number
Normal Operation
The heated seat module receives battery voltage on circuit SBP18 (YE/RD) and ignition voltage on circuit CBP35 (YE/GY), and is supplied ground on circuit GD143 (BK/VT). With the ignition switch in RUN or START, when the left rear heated seat control switch is pressed, a ground is supplied on circuit CHS46 (YE/GN) to command the system on or off in high heat mode or circuit CHS47 (VT/GN) to command the system on or off in low heat mode. When the right rear heated seat control switch is pressed with the ignition switch in RUN or START, a ground is supplied on circuit CHS50 (BU/GY) to command the system on or off in high heat mode or circuit CHS51 (YE/GY) to command the system on or off in low heat mode. When commanded on, voltage is supplied to the heated seat switch from the heated seat module on either circuit CHS48 (YE) (left rear) or CHS52 (BU) (right rear) (high heat mode) or circuit CHS49 (VT) (left rear) or CHS53 (WH/BN) (right rear) (low 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) (left rear) or CHS43 (GY/BU) (right rear) and ground to the heater mats on circuit GD147 (BK/VT) (left rear) or GD148 (BK/YE) (right rear). 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 monitors the temperature sensors on circuit VHS42 (GN) (left rear) or VHS45 (GY/BN) (right rear) for adjusting the current flow to the heater mats and uses a ground supplied on circuit RHS41 (GN/BN). The heated seat module is designed to remain on, heating the seat and maintaining temperature until switched off or the ignition voltage is switched OFF.
A new heated seat module must be configured after installation for correct operation. To configure, press the low heat mode button on either rear heated seat switch. Module configuration will occur automatically after the low heat mode button is pressed. Until the module is correctly configured, the heated seats will operate incorrectly when selecting the high heat mode by following a sequence of high, low and off with each button press. The system will operate correctly after the heated seat module receives a low heat request on either of the low heat request circuits and rear heated seat module configuration is activated.
This pinpoint test is intended to diagnose the following:
- Fuse(s)
- Wiring, terminals or connectors
- Heated seat module
PINPOINT TEST R: THE HEATED SEATS ARE INOPERATIVE - REAR
NOTICE: Use the correct probe adapter(s) from the Flex Probe Kit when taking measurements. Failure to use the correct probe adapter(s) may damage the connector.
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R1 CHECK FOR VOLTAGE TO THE REAR HEATED SEAT MODULE
- Disconnect: Heated Seat Module C3054B.
- Ignition ON.
- Measure the voltage between:
- heated seat module C3054B-2, circuit CBP35 (YE/GY), harness side and ground.
- heated seat module C3054B-1, circuit SBP18 (YE/RD), harness side and ground.
- Are the voltages greater than 10 volts?
Yes
GO to R2.
No
VERIFY Smart Junction Box (SJB) fuses 18 (20A) and 35 (10A) are OK. If OK, REPAIR the circuit(s). 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
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R2 CHECK THE HEATED SEAT MODULE GROUND CIRCUIT FOR AN OPEN
- Ignition OFF.
- Measure the resistance between heated seat module C3054B-5, circuit GD143 (BK/VT), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
GO to R3.
No
REPAIR the circuit(s). TEST the system for normal operation.
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R3 CHECK THE REAR HEATED SEAT SWITCH INPUT GROUND CIRCUIT FOR AN OPEN
- 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 driver 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 R4.
No
REPAIR circuit GD143 (BK/VT). TEST the system for normal operation.
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R4 CHECK THE TEMPERATURE SENSOR RETURN CIRCUIT FOR AN OPEN
- Measure the resistance between heated seat module C3054A-12, circuit RHS41 (GN/BN), harness side and left rear heated seat C3054A-3, circuit VHS42 (GN), harness side.
- Is the resistance between 300 and 300,000 ohms?
Yes
GO to R5.
No
REPAIR circuit RHS41 (GN/BN). TEST the system for normal operation.
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R5 CHECK THE HEATER MATS GROUND CIRCUIT 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
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
REPAIR circuit GD150 (BK/WH). TEST the system for normal operation.
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