Pinpoint Test 8: The Heated Seat Is Inoperative/Does Not Operate Correctly - Passenger

PINPOINT TEST 8: THE HEATED SEAT IS INOPERATIVE/DOES NOT OPERATE CORRECTLY - PASSENGER

WARNING:Never probe the electrical connectors on safety belt buckle/retractor pretensioners or adaptive load limiting retractors. Failure to follow this instruction may result in the accidental deployment of the safety belt pretensioners or adaptive load limiting retractors, which increases the risk of serious personal injury or death.

WARNING:Never probe the electrical connectors on air bag, safety canopy or side air curtain modules. Failure to follow this instruction may result in the accidental deployment of these modules, which increases the risk of serious personal injury or death.

CAUTION:Use the correct probe adapter(s) when taking measurements. Failure to use the correct probe adapter(s) may damage the connector.
NOTE:Most faults are due to connector and/or wiring concerns. Carry out a thorough inspection and verification before proceeding with the Pinpoint Test.See - Seats - Principles Of Operation or - Symptom Related Diagnostic Procedures for direction to the appropriate Pinpoint Test.

Normal Operation

The HVAC module contains the passenger heated seat control button and indicator. The heated seat system operates independently from the climate control system and the engine must be running. A heated seat relay is located underneath the passenger seat cushion frame. There are 2 voltage supplies to the heated seat relay. Voltage is supplied from the Smart Junction Box (SJB) heated seat relay enable circuit (GY) to the passenger heated seat relay coil. Ground is supplied to the opposite side of the passenger relay coil by the HVAC module from the heated seat relay drive circuit (GY/E) when the passenger heated seat switch button is pressed to energize the relay. This closes the relay contacts to supply battery voltage from the SJB circuit (Y/R) to the passenger heater mat circuit (Y/G). The passenger heater mats are directly connected to ground circuit (B/GY) completing the electrical circuit to heat the seat.

- DTC B12AD (Passenger Heated Seat Relay Drive Circuit Shorted to Battery Voltage) - if the passenger heated seat relay drive circuit is shorted to voltage and the HVAC module attempts to activate the passenger heated seat relay, the DTC will set and the seat will fail to heat or intermittently heat.
- DTC B12AE (Passenger Heated Seat Relay Drive Circuit Open or Shorted to Ground) - if the passenger heated seat relay drive circuit is open or shorted to ground and the HVAC module attempts to activate the passenger heated seat relay, the DTC will set and the seat will fail to heat or intermittently heat.

Possible Causes
- Wiring, terminals or connectors
- Heated seat relay
- Heated seat element
- HVAC module

Diagnostic Procedure

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.