Pinpoint Test T: The Heated Seats Are Inoperative - Rear
Seats
Pinpoint Tests
Pinpoint Test T: 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 SBB05 (GY/RD) and ignition voltage on circuit CBP35 (YE/GY), and is supplied ground on circuit GD133 (BK). When the left rear heated seat control switch is pressed with the ignition switch in RUN or START, 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 ignition voltage is switched OFF.
This pinpoint test is intended to diagnose the following:
- Fuse(s)
- Wiring, terminals or connectors
- Heated seat module
PINPOINT TEST T: THE HEATED SEATS ARE INOPERATIVE - REAR
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T1 CHECK VOLTAGE TO THE REAR HEATED SEAT MODULE
- Disconnect: Rear Heated Seat Module C3162.
- Ignition ON.
- Measure the voltage between:
- rear heated seat module C3162-2, circuit CBP35 (YE/GY), harness side and ground.
- rear heated seat module C3162-1, circuit SBB05 (GY/RD), harness side and ground.
- Are the voltages greater than 10 volts?
Yes
GO to T2.
No
VERIFY Battery Junction Box (BJB) fuse 5 (20A) and Smart Junction Box (SJB) fuse 35 (10A) are 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.
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T2 CHECK THE REAR HEATED SEAT MODULE GROUND CIRCUIT FOR AN OPEN
- Ignition OFF.
- Measure the resistance between rear heated seat module C3162-7, circuit GD133 (BK), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
GO to T3.
No
REPAIR the circuit. TEST the system for normal operation.
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T3 CHECK THE HEATED SEAT SENSOR RETURN CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition ON.
- Measure the voltage between rear heated seat module C3162-13, circuit RHS41 (GN/BN), harness side and ground.
- Is there any voltage present?
Yes
REPAIR the circuit. TEST the system for normal operation.
No
GO to T4.
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T4 CHECK THE HEATED SEAT SENSOR RETURN CIRCUIT FOR SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between rear heated seat module C3162-13, circuit RHS41 (GN/BN), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to T5.
No
REPAIR the circuit. TEST the system for normal operation.
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T5 CHECK THE HEATED SEAT SENSOR RETURN CIRCUIT FOR AN OPEN
- Disconnect: Right Rear Heated Seat C3169.
- Measure the resistance between heated seat module C3162-13, circuit RHS41 (GN/BN), harness side and right rear heated seat C3169-3, circuit RHS41 (GN/BN), harness side.
- Is the resistance less than 5 ohms?
Yes
INSTALL a new rear heated seat module. REFER to Heated Seat Module - Rear Heated Seat Module - Rear. TEST the system for normal operation.
No
REPAIR the circuit. TEST the system for normal operation.
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