Pinpoint Test P: The Heated Seat Does Not Operate Correctly - Front Seat Indicator Does Not Illuminate when pressed

Seats

Pinpoint Test P: The Heated Seat Does Not Operate Correctly - Front Seat Does Heat But the Heated Seat Indicator Does Not Illuminate When Pressed

Normal Operation

When commanded on, the heated seat module supplies voltage to the HVAC module to illuminate the appropriate HI/LOW indicators.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- Heated seat module

- HVAC module

- Front Controls Interface Module (FCIM) (if equipped with navigation)

PINPOINT TEST P : THE HEATED SEAT DOES NOT OPERATE CORRECTLY - FRONT SEAT DOES HEAT BUT THE HEATED SEAT INDICATOR DOES NOT ILLUMINATE WHEN PRESSED

NOTE:
If a seat equipped with a seat mounted side air bag is being repaired, the Supplemental Restraint System (SRS) must be depowered. Refer to Restraints and Safety Systems &/or Air Bag Systems.
NOTE:
The air bag warning lamp illuminates when the Restraints Control Module (RCM) fuse is removed and the ignition switch is ON. This is normal operation and does not indicate an SRS (Supplemental Restraint System) fault.
NOTE:
The SRS (Supplemental Restraint System) must be fully operational and free of faults before releasing the vehicle to the customer.

P1 CHECK THE INDICATOR CIRCUIT(S) FOR AN OPEN AND SHORT TO GROUND

- Ignition OFF.

- Depower the SRS (Supplemental Restraint System). Refer to Restraints and Safety Systems &/or Air Bag Systems.

- Disconnect: Driver Seat Side Air Bag Module C3051.

- Disconnect: Passenger Seat Side Air Bag Module C339.

- Disconnect: HVAC Module C2109B or C228B (vehicles with navigation).

- Disconnect: Heated Seat Module C359A.

- Measure the resistance between the HVAC module and heated seat module; and between the HVAC module and ground using the illustration and appropriate chart:

Vehicles Equipped With Navigation

Inoperative Indicator Positive Meter Lead Negative Meter Lead Circuit Driver Low Heat Indicator C228B-7 C359A-4, then ground CHS04 (YE/GY) Driver High Heat Indicator C228B-8 C359A-5, then ground CHS13 (VT/BN) Passenger Low Heat Indicator C228B-4 C359A-10, then ground CHS09 (GY) Passenger High Heat Indicator C228B-5 C359A-11, then ground CHS14 (GN)

Vehicles Without Navigation

Inoperative Indicator Positive Meter Lead Negative Meter Lead Circuit Driver Low Heat Indicator C2109B-20 C359A-4, then ground CHS04 (YE)/(YE/GY) Driver High Heat Indicator C2109B-21 C359A-5, then ground CHS13 (VT)/(VT/BN) Passenger Low Heat Indicator C2109B-17 C359A-10, then ground CHS09 (GY) Passenger High Heat Indicator C2109B-18 C359A-11, then ground CHS14 (GN)

Is the resistance less than 5 ohms between the HVAC module and heated seat module and greater than 10,000 ohms between the HVAC module and ground?

Yes
For driver seat, GO to P2.

For passenger seat, GO to P3.
No
REPAIR the circuit(s). TEST the system for normal operation.

DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C3051 and passenger seat side air bag module C339. REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

P2 CHECK THE HEATED SEAT MODULE INDICATOR OUTPUT CIRCUITS FOR VOLTAGE

- Connect: HVAC Module C2109B or C228B (vehicles with navigation).

- Connect: Heated Seat Module C359A.

- 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.

- Start the engine.

- Back-probe the heated seat module electrical connector and measure the voltage between the following, while operating the heated seat on and off:
- heated seat module C359A-4, circuit CHS04 (YE/GY), harness side and ground.

- heated seat module C359A-5, circuit CHS13 (VT/BN), harness side and ground.

Is there less than 1 volt when off and greater than 10 volts when on?

Yes
For vehicles without navigation, INSTALL a new HVAC module.

For vehicles with navigation, INSTALL a new FCIM (Front Controls Interface Module).

TEST the system for normal operation.

DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C3051 and passenger seat side air bag module C339. REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
No
INSTALL a new heated seat module. REFER to Heated Seat Module - Front . TEST the system for normal operation.

DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C3051 and passenger seat side air bag module C339. REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

P3 CHECK THE HEATED SEAT MODULE INDICATOR OUTPUT CIRCUITS FOR VOLTAGE

- Connect: HVAC Module C2109B or C228B (vehicles with navigation).

- Connect: Heated Seat Module C359A.

- 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.

- Start the engine.

- Back-probe the heated seat module electrical connector and measure the voltage between the following, while operating the heated seat on and off:
- heated seat module C359A-10, circuit CHS09 (GY), harness side and ground.

- heated seat module C359A-11, circuit CHS14 (GN), harness side and ground.