Pinpoint Test N: The Heated Seat Is Inoperative - Driver Or Passenger
Seats
Pinpoint Tests
Pinpoint Test N: The Heated Seat is Inoperative - Driver or Passenger
Refer to Wiring Diagram Set 119, Climate Controlled Seats for schematic and connector information. Diagrams By Number
Normal Operation
The driver and passenger heated seats share a common ignition and battery feed to the heated seat control switch assembly. Ignition feed circuit CBP18 (GY/OG) supplies voltage to the logic board and illumination of the heated seat switch assembly and the battery feed circuit SBB28 (GN/RD) is used to provide voltage to the heater mats. The heated seat switch assembly uses shared ground GD145 (BK/BU) for the logic board and illumination.
When a heated seat switch is pressed with the ignition switch in RUN or START, a momentary ground is provided to the logic board of the heated seat switch assembly. The logic board then activates an internal relay in the heated seat switch assembly that provides voltage via circuit CHS02 (YE/BU) (driver seat) or CHS07 (GY/BU) (front passenger seat) to the bi-metallic thermostat that is part of the seat cushion heater mat.
The driver seat cushion and backrest heater mats are wired in series as are the passenger seat cushion and backrest heater mats. The heated seat system is designed to maintain the temperature by the opening (no voltage to the heated seat elements) and closing (voltage supplied to the heated seat elements) of the bi-metallic thermostat.
This pinpoint test is intended to diagnose the following:
- Fuse(s)
- Wiring, terminals or connectors
- Heated seat switch
- Heated seat relay
- Heated seat mat
PINPOINT TEST N: THE HEATED SEAT IS INOPERATIVE - DRIVER OR 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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N1 CHECK CIRCUIT SSB28 (GN/RD) FOR VOLTAGE
- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in the General Procedures portion of Restraint Systems.
- For heated seat diagnostics on the driver seat, carry out the following:
- disconnect: Driver Seat Safety Belt Buckle Pretensioner C3201.
- disconnect: Driver Seat Side Air Bag C3049.
- For heated seat diagnostics on the passenger seat, carry out the following:
- disconnect: Passenger Seat Safety Belt Buckle Pretensioner C3202.
- disconnect: Passenger Seat Side Air Bag C3050.
- Disconnect: Heated Seat Switch C2347 .
- 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.
- For driver seat, measure the voltage at heated seat switch C2347-3, circuit SBB28 (GN/RD), harness side and ground.
- For passenger seat, measure the voltage at heated seat switch C2347-5, circuit SBB28 (GN/RD), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to N2.
No
VERIFY Battery Junction Box (BJB) fuse 28 (20A) is OK. If OK, REPAIR circuit SBB28 (GN/RD). 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
DISCONNECT the battery ground cable.
CONNECT safety belt buckle and pretensioner C3201 (driver) or C3202 (passenger).
CONNECT seat side air bag module C3049 (driver) or C3050 (passenger).
REPOWER the SRS. REFER to Restraint Systems.
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N2 CHECK CIRCUIT CHS02 (YE/BU) (DRIVER) OR CHS07 (GY/BU) (PASSENGER) FOR AN OPEN
- Ignition OFF.
- Disconnect: Heated Seat Cushion Element C364 (Driver) or C334 (Passenger).
- For driver seat, measure the resistance between heated seat switch C2347-4, circuit CHS02 (YE/BU), harness side and driver heated seat cushion element C364-1, circuit CHS02 (YE/BU), harness side.
- For passenger seat, measure the resistance between heated seat switch C2347-2, circuit CHS07 (GY/BU), harness side and passenger heated seat cushion element C334-1, circuit CHS07 (GY/BU), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to N3.
No
REPAIR driver circuit CHS02 (YE/BU) or passenger circuit CHS07 (GY/BU). TEST the system for normal operation.
DISCONNECT the battery ground cable.
CONNECT safety belt buckle and pretensioner C3201 (driver) or C3202 (passenger).
CONNECT seat side air bag module C3049 (driver) or C3050 (passenger).
REPOWER the SRS. REFER to Restraint Systems.
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N3 CHECK CIRCUIT CHS02 (YE/BU) (DRIVER) OR CHS07 (GY/BU) (PASSENGER) FOR A SHORT TO GROUND
- For driver seat, measure the resistance between heated seat cushion element C364-1, circuit CHS02 (YE/BU), harness side and ground.
- For passenger seat, measure the resistance between heated seat cushion element C334-1, circuit CHS07 (GY/BU), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to N4.
No
REPAIR driver circuit CHS02 (YE/BU) or passenger circuit CHS07 (GY/BU). TEST the system for normal operation.
DISCONNECT the battery ground cable.
CONNECT safety belt buckle and pretensioner C3201 (driver) or C3202 (passenger).
CONNECT seat side air bag module C3049 (driver) or C3050 (passenger).
REPOWER the SRS. REFER to Restraint Systems.
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N4 CHECK HEATED SEAT CUSHION ELEMENT FOR AN OPEN
- Measure the resistance between driver heated seat cushion element C364-1 and C364-2, component side; or between passenger heated seat cushion element C334-1 and C334-2, component side.
- Is the resistance between 0.8 and 2.0 ohms?
Yes
GO to N5.
No
INSTALL a new heated seat cushion element. TEST the system for normal operation.
DISCONNECT the battery ground cable.
CONNECT safety belt buckle and pretensioner C3201 (driver) or C3202 (passenger).
CONNECT seat side air bag module C3049 (driver) or C3050 (passenger).
REPOWER the SRS. REFER to Restraint Systems.
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N5 CHECK DRIVER HEATED SEAT CIRCUIT CHS01 (GY/VT) OR PASSENGER CIRCUIT CHS06 (BU/BN) FOR AN OPEN
- Disconnect: Seat Back Heater C365 (Driver) or C335 (Passenger).
- Measure the resistance between driver heated seat cushion element C364-2, circuit CHS01 (GY/VT), harness side and driver heated seat backrest element C365-1, circuit CHS01 (GY/VT), harness side; or between passenger heated seat cushion element C334-2, circuit CHS06 (BU/BN), harness side and passenger heated seat backrest element C335-1, circuit CHS06 (BU/BN), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to N6.
No
REPAIR driver circuit CHS01 (GY/VT) or passenger circuit CHS06 (BU/BN). TEST the system for normal operation.
DISCONNECT the battery ground cable.
CONNECT safety belt buckle and pretensioner C3201 (driver) or C3202 (passenger).
CONNECT seat side air bag module C3049 (driver) or C3050 (passenger).
REPOWER the SRS. REFER to Restraint Systems.
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N6 CHECK DRIVER HEATED SEAT CIRCUIT CHS01 (GY/VT) OR PASSENGER CIRCUIT CHS06 (BU/BN) FOR A SHORT TO GROUND
- Measure the resistance between driver heated seat cushion element C364-2, circuit CHS01 (GY/VT) or passenger heated seat cushion element C334-2, circuit CHS06 (BU/BN), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to N7.
No
REPAIR driver circuit CHS01 (GY/VT) or passenger circuit CHS06 (BU/BN). TEST the system for normal operation.
DISCONNECT the battery ground cable.
CONNECT safety belt buckle and pretensioner C3201 (driver) or C3202 (passenger).
CONNECT seat side air bag module C3049 (driver) or C3050 (passenger).
REPOWER the SRS. REFER to Restraint Systems.
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N7 CHECK HEATED SEAT BACKREST ELEMENT FOR AN OPEN
- Measure the resistance between driver heated seat backrest element C365-1 and C365-2, component side; or between passenger heated seat backrest element C335-1 and C335-2, component side.
- Is the resistance between 0.8 and 2.0 ohms?
Yes
GO to N8.
No
INSTALL a new heated seat back element. TEST the system for normal operation.
DISCONNECT the battery ground cable.
CONNECT safety belt buckle and pretensioner C3201 (driver) or C3202 (passenger).
CONNECT seat side air bag module C3049 (driver) or C3050 (passenger).
REPOWER the SRS. REFER to Restraint Systems.
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N8 CHECK DRIVER CIRCUIT GD133 (BK) OR PASSENGER CIRCUIT GD151 (BK/GN) FOR AN OPEN
- Measure the resistance between driver heated seat backrest element C365-2, circuit GD133 (BK) or passenger C335-2, circuit GD151 (BK/GN), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
INSTALL a new heated seat switch. REFER to Heated Seat Switch Heated Seat Switch. TEST the system for normal operation.
DISCONNECT the battery ground cable.
CONNECT safety belt buckle and pretensioner C3201 (driver) or C3202 (passenger).
CONNECT seat side air bag module C3049 (driver) or C3050 (passenger).
REPOWER the SRS. REFER to Restraint Systems.
No
REPAIR driver circuit GD133 (BK) or passenger circuit GD151 (BK/GN). TEST the system for normal operation.
DISCONNECT the battery ground cable.
CONNECT safety belt buckle and pretensioner C3201 (driver) or C3202 (passenger).
CONNECT seat side air bag module C3049 (driver) or C3050 (passenger).
REPOWER the SRS. REFER to Restraint Systems.
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