Pinpoint Test J: The Heated Seat Is Inoperative - Driver Seat Does Not Heat But The Heated Seat Indicator Illuminates When Pres
Seats
Pinpoint Tests
Pinpoint Test J: The Heated Seat is Inoperative - Driver Seat Does Not Heat But the Heated Seat Indicator Illuminates When Pressed
Normal Operation
The HVAC module includes the heated seat switch buttons and indicators. The heated seat system will function when the HVAC module is on or off. There is a relay box located behind the headlamp switch area containing 2 micro relays for the driver and passenger heated seats. Battery voltage from circuit 1048 (LB/WH) is supplied to the coil and switch side of the driver heated seat relay. When the ignition switch is ON and the engine running, ground is supplied to the driver heated seat relay coil from the driver heated seat switch in the HVAC module to energize the relay. This closes the relay switch supplying voltage to driver seat cushion heater mat from circuit 1064 (YE/LB). The cushion and backrest heater mats are connected in series by circuit 1066 (GN/LB) and ground is supplied to backrest heater mat circuit 1205 (BK), completing the heater mat circuit to heat the driver seat. If the heated seat switch is on when the ignition switch is turned OFF, the heated seat switch will be on when the ignition switch is turned back ON.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Heated seat switch (part of HVAC module)
- Heated seat relay
- Cushion heater mat
- Backrest heater mat
PINPOINT TEST J: THE HEATED SEAT IS INOPERATIVE - DRIVER SEAT DOES NOT HEAT BUT THE HEATED SEAT INDICATOR ILLUMINATES WHEN PRESSED
WARNING: Remove restraint system diagnostic tools from the vehicle prior to road testing. If tools are not removed, the supplemental restraint system (SRS) device may not deploy in a crash. Failure to follow this instruction may result in serious personal injury or death in a crash and possibly violate vehicle safety standards.
NOTICE: Use the correct probe adapter(s) from the Flex Probe Kit when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
NOTICE: Most faults are due to connector and/or wiring concerns. Carry out a thorough inspection and verification before proceeding with the pinpoint test. Inspection and Verification
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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J1 CHECK CIRCUIT 1064 (YE/LB) FOR VOLTAGE
- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in the General Procedures of Air Bag Systems.
- Disconnect: Driver Seat Side Air Bag C367.
- Connect: Restraint System Diagnostic Service Tool 418-133 to Driver Seat Side Air Bag C367.
- Disconnect: Driver Heated Seat C3300.
- 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.
- Ignition ON.
- Measure voltage between driver heated seat C3300-1, circuit 1064 (YE/LB), harness side and ground.
- Is voltage greater than 10 volts when the heated seat switch is depressed and 0 volt when the switch is off?
Yes
GO to J6.
No
GO to J2.
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J2 CHECK THE HEATED SEAT RELAY
- Ignition OFF.
- Swap the passenger heated seat relay with the driver heated seat relay.
- Ignition ON.
- Does the seat heat when the heated seat switch is depressed?
Yes
INSTALL a new heated seat relay. TEST the system for normal operation.
DISCONNECT the battery ground cable. DISCONNECT the Restraint System Diagnostic Service Tool from driver seat side air bag module C367. CONNECT driver seat side air bag module C367. REPOWER the SRS. REFER to Air Bag Systems.
No
GO to J3.
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J3 CHECK VOLTAGE TO THE HEATED SEAT RELAY
- Ignition OFF.
- Disconnect: Heated Seat Relay (Driver).
- Measure voltage between:
- driver heated seat relay socket pin 1, circuit 1048 (LB/WH), harness side and ground.
- driver heated seat relay socket pin 3, circuit 1048 (LB/WH), harness side and ground.
- Are both voltages greater than 10 volts?
Yes
GO to J4.
No
REPAIR the circuit. TEST the system for normal operation.
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J4 CHECK CIRCUIT 1064 (YE/LB) FOR AN OPEN
- Measure resistance between driver heated seat relay socket pin 5, circuit 1064 (YE/LB) and driver cushion heater mat C3300-1 circuit 1064 (YE/LB), harness side.
- Is resistance less than 5 ohms?
Yes
GO to J5.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag C367.
REPOWER the SRS. REFER to Air Bag Systems.
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J5 CHECK HEATED SEAT REQUEST CIRCUIT VOLTAGE
- Connect: Driver Heated Seat Relay.
- Disconnect: HVAC Module C294a.
- Measure voltage between HVAC module C294a-12, circuit 581 (RD), harness side and ground.
- Is voltage greater than 10 volts?
Yes
INSTALL a new HVAC module.
No
REPAIR the circuit. TEST the system for normal operation.
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J6 CHECK CIRCUIT 1205 (BK) FOR AN OPEN
- Ignition OFF.
- Disconnect: Driver Heated Seat C3310.
- Measure resistance between driver seat C3310-2 circuit 1205 (BK), harness side and ground.
- Is resistance less than 5 ohms?
Yes
GO to J7.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. DISCONNECT the Restraint System Diagnostic Service Tool from driver seat side air bag module C367. CONNECT driver seat side air bag module C367. REPOWER the SRS. REFER to Air Bag Systems.
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J7 CHECK THE CUSHION HEATER MAT FOR AN OPEN
- Measure resistance between driver cushion heater mat C3300 pins 1 and 2, component side.
- Is resistance between 0.8 and 1.3 ohms?
Yes
GO to J8.
No
INSTALL a new cushion heater mat. REFER to Seat Cushion Cover - Front Front Seat Cushion Cover. TEST the system for normal operation.
DISCONNECT the battery ground cable. DISCONNECT the Restraint System Diagnostic Service Tool from driver seat side air bag module C367. CONNECT driver seat side air bag module C367. REPOWER the SRS. REFER to Air Bag Systems.
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J8 CHECK THE BACKREST HEATER MAT FOR AN OPEN
- Disconnect: Driver Backrest Heater Mat C3310.
- Measure resistance between backrest heater mat C3310 pins 1 and 2, component side.
- Is resistance between 0.8 and 1.3 ohms?
Yes
REPAIR seat harness. TEST the system for normal operation.
DISCONNECT the battery ground cable. DISCONNECT the Restraint System Diagnostic Service Tool from driver seat side air bag module C367. CONNECT driver seat side air bag module C367. REPOWER the SRS. REFER to Air Bag Systems.
No
INSTALL a new backrest heater mat. REFER to Seat Cushion Cover - Front Front Seat Cushion Cover. TEST the system for normal operation.
DISCONNECT the battery ground cable. DISCONNECT the Restraint System Diagnostic Service Tool from driver seat side air bag module C367. CONNECT driver seat side air bag module C367. REPOWER the SRS. REFER to Air Bag Systems.
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