Pinpoint Test N: The Heated Seat is Inoperative - Driver
Seats
Pinpoint Test N: The Heated Seat is Inoperative - Driver
Normal Operation
The heated seat module is supplied with 2 battery voltage inputs (one for the driver seat and one for the passenger seat), a single ignition voltage input and a single ground circuit. If equipped with navigation and the heated seat buttons on the Front Controls Interface Module (FCIM) are pressed, the FCIM (Front Controls Interface Module) sends a request message to the HVAC module which controls the heated seats by supplying a momentary ground to the heated seat module. If not equipped with navigation, the HVAC module controls the heated seats by supplying a momentary ground to the heated seat module when a heated seat button on the HVAC is pressed.
Upon receiving the request, the heated seat module supplies voltage to the appropriate driver and/or passenger seat cushion and backrest heater mats, which are connected in series. The driver and passenger heater mats share a common ground circuit. Temperature is maintained by the heated seat module using a sensor contained within the cushion heater mat. The heated seat module supplies a reference voltage to the temperature sensor and monitors the return signal from the temperature sensor for controlling current flow to the heater mats. The heated seat module remains on, heating the seat and maintaining temperature until commanded off from the HVAC module (or until the ignition is turned OFF).
- DTC B1030:11 (Left Front Seat Heater: Circuit Short To Ground)- If the driver seat request circuit from the HVAC module to the heated seat module is shorted to ground, the DTC is set.
- DTC B1030:12 (Left Front Seat Heater: Circuit Short To Battery)- If the driver seat request circuit from the HVAC module to the heated seat module is shorted to voltage, the DTC is set.
- DTC B1030:13 (Left Front Seat Heater: Circuit Open)- If the driver seat request circuit from the HVAC module to the heated seat module is open, the DTC is set.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Heater mat
- Heated seat module
- HVAC module
- FCIM (Front Controls Interface Module) (if equipped with navigation)
PINPOINT TEST N : THE HEATED SEAT IS INOPERATIVE - DRIVER
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.
N1 CHECK HEATED SEAT OPERATION
- Start the engine.
- Verify the passenger heated seat is operational.
Is the passenger heated seat operational?
Yes
If equipped with navigation, GO to N2.
If not equipped with navigation, GO to N4.
No
GO to Pinpoint Test M. Pinpoint Test M: The Heated Seats are Inoperative - Both Front Seats
N2 CHECK FOR FCIM (Front Controls Interface Module) DTCs
- Enter the following diagnostic mode on the scan tool: Self Test- FCIM (Front Controls Interface Module).
- Retrieve and record all FCIM (Front Controls Interface Module) DTCs.
Are any DTCs retrieved?
Yes
REFER to the DTC Chart in Accessories and Optional Equipment. Accessories and Optional Equipment
No
GO to N3.
N3 MONITOR FCIM (Front Controls Interface Module) DRIVER HEATED SEAT (CC_SW_D_HSEATS) PID
- Enter the following diagnostic mode on the scan tool: DataLogger- FCIM (Front Controls Interface Module).
- Monitor the FCIM (Front Controls Interface Module) CC_SW_D_HSEATS PID while pressing the driver heated seat button.
Do the PID status agree with the button setting?
Yes
GO to N4.
No
INSTALL a new FCIM (Front Controls Interface Module). TEST the system for normal operation.
N4 CHECK FOR HVAC MODULE DTCs
- Enter the following diagnostic mode on the scan tool: Self Test- HVAC module.
- Retrieve and record all HVAC DTCs.
Are any HVAC module DTCs retrieved?
Yes
If DTC B1030:12, GO to N19.
If DTC B1030:13, GO to N20.
If DTC B1030:11, GO to N21.
For all other HVAC module DTCs, REFER to Heating and Air Conditioning.
No
If equipped with navigation, GO to N5.
If not equipped with navigation, GO to N6.
N5 CHECK THE OTHER HVAC FUNCTIONS
NOTE: The purpose of this step is to verify the HVAC module is able to receive and process inbound command messages from the communication bus and demonstrate the HVAC module is operational.
- Operate the other HVAC systems (rear defrost, blower fan, temperature control, etc.) and verify the operation.
Do the other HVAC systems function correctly?
Yes
GO to N7.
No
REFER to Heating and Air Conditioning to diagnose the HVAC system.
N6 MONITOR HVAC MODULE LEFT SEAT HEATER (ST_HEAT_LT) PID
- Enter the following diagnostic mode on the scan tool: DataLogger- HVAC module.
- NOTE: The PID data will quickly flicker on and off. Watch closely when pressing the switch button.
Monitor HVAC module ST_HEAT_LT PID while pressing driver heated seat button.
Do the PID status agree with the button setting?
Yes
GO to N7.
No
INSTALL a new HVAC module. TEST the system for normal operation.
N7 CHECK FOR VOLTAGE TO THE HEATED SEAT MODULE
- 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: Heated Seat Module C359B.
- 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.
- Measure the voltage between heated seat module C359B-1, circuit CBX01 (GN/RD), harness side and ground.
Is the voltage greater than 10 volts?
Yes
GO to N8.
No
VERIFY Battery Junction Box (BJB) fuse 69 (30A) is OK. If OK, REPAIR the circuit. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short [1][2]Diagrams By Number. 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.
N8 CHECK RESISTANCE OF THE DRIVER SEAT HEATER MATS AND HEATER CIRCUITS
- Measure the resistance between heated seat module C359B-4, circuit CHS02 (YE/BU), harness side and ground.
Is the resistance between 2 and 4 ohms?
Yes
GO to N14.
No
GO to N9.
N9 CHECK THE DRIVER SEAT CUSHION HEATER CIRCUIT FOR AN OPEN OR SHORT TO GROUND
- Disconnect: Driver Seat Cushion Heater Mat C364.
- Measure the resistance between:
- heated seat module C359B-4, circuit CHS02 (YE/BU), harness side and driver seat cushion heater mat C364-1, circuit CHS02 (YE/BU), harness side.
- heated seat module C359B-4, circuit CHS02 (YE/BU), harness side and ground.
Is the resistance less than 0.5 ohm between C359B-4 and C364-1 and greater than 10,000 ohms between C359B-4 and ground?
Yes
GO to N10.
No
REPAIR the circuit. 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.
N10 CHECK THE CUSHION HEATER MAT FOR AN OPEN
- Measure the resistance between driver seat cushion heater mat C364 pins 1 and 4, component side.
Is the resistance between 1.6 and 2.0 ohms?
Yes
GO to N11.
No
INSTALL a new driver seat cushion heater mat. REFER to Seat Cushion Heater Mat - 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.
N11 CHECK FOR AN OPEN BETWEEN THE CUSHION AND BACKREST HEATER MATS
- Disconnect: Driver Seat Backrest Heater Mat C365.
- Measure the resistance between seat cushion heater mat C364-4, circuit CHS01 (GY/VT), harness side and seat backrest heater mat C365-1, circuit CHS01 (GY/VT), harness side.
Is the resistance less than 0.5 ohm?
Yes
GO to N12.
No
REPAIR the circuit. 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.
N12 CHECK THE BACKREST HEATER MAT FOR AN OPEN
- Measure the resistance between driver seat backrest heater mat C365 pins 1 and 2, component side.
Is the resistance between 0.9 and 1.1 ohm?
Yes
GO to N13.
No
INSTALL a new driver seat backrest heater mat. REFER to Seat Backrest Heater Mat - 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.
N13 CHECK THE HEATER MAT GROUND CIRCUIT FOR AN OPEN
- Measure the resistance between driver seat backrest heater C365-2, circuit GD904 (BK/BU), harness side and ground.
Is the resistance less than 0.5 ohms?
Yes
The fault is intermittent. CHECK the electrical connectors for corrosion, poor pin contact or pushed out pins, particularly the pins and terminals of electrical connectors that were disconnected. Do not install any new components at this time. Components should only be installed when directed to do so in the pinpoint test. REPAIR any intermittent wiring, terminal or connector concerns found. 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
REPAIR the circuit. 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.
N14 CHECK HEATED SEAT TEMPERATURE SENSOR CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: Heated Seat Module C359A.
- Ignition ON.
- Measure the voltage between heated seat module C359A-3, circuit VHS26 (VT), harness side and ground.
Is any voltage present?
Yes
REPAIR the circuit. GO to N18 to check the temperature sensor for damage. If OK, TEST the system for normal operation. If not OK, INSTALL a new cushion heater mat. REFER to Seat Cushion Heater Mat - Front . TEST the system for normal operation.
DISCONNECT the battery ground cable.
CONNECT passenger seat side air bag module C339.
CONNECT driver seat side air bag module C3051.
REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
No
GO to N15.
N15 CHECK THE TEMPERATURE SENSOR AND CIRCUITS FOR AN OPEN
- Ignition OFF.
- Measure the resistance between heated seat module C359A-3, circuit VHS26 (VT), and C359A-12, circuit RHS05 (YE-VT), harness side.
Is the resistance between 300 and 300K ohms?
Yes
GO to N19.
No
GO to N16.
N16 CHECK TEMPERATURE SENSOR CIRCUIT FOR AN OPEN AND SHORT TO GROUND
- Disconnect: Driver Seat Cushion Heater Mat C364.
- Measure the resistance between:
- heated seat module C359A-3, circuit VHS26 (VT), harness side and seat cushion heater mat C364-2, circuit VHS26 (VT), harness side.
- heated seat module C359A-3, circuit VHS26 (VT), harness side and ground.
Is the resistance less than 5 ohms between C359A-3 and C364-2, and greater than 10,000 ohms between C359A-3 and ground?
Yes
GO to N17.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable.
CONNECT passenger seat side air bag module C339.
CONNECT driver seat side air bag module C3051.
REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
N17 CHECK TEMPERATURE SENSOR RETURN CIRCUIT FOR AN OPEN
- Measure the resistance between heated seat module C359A-12, circuit RHS05 (YE/VT), harness side and driver seat cushion heater mat C364-3, circuit RHS05 (YE/VT), harness side.
Is the resistance less than 5 ohms?
Yes
GO to N18.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable.
CONNECT passenger seat side air bag module C339.
CONNECT driver seat side air bag module C3051.
REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
N18 CHECK HEATED SEAT TEMPERATURE SENSOR FOR AN OPEN
- Measure the resistance between heated seat cushion C364 pins 2 and 3, component side.
Is the resistance between 300 ohms and 300K ohms?
Yes
GO to N19.
No
INSTALL a new seat cushion heater mat. REFER to Seat Cushion Heater Mat - Front . TEST the system for normal operation.
DISCONNECT the battery ground cable.
CONNECT passenger seat side air bag module C339.
CONNECT driver seat side air bag module C3051.
REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
N19 CHECK THE HEATED SEAT MODULE SWITCH REQUEST CIRCUIT FOR A SHORT TO VOLTAGE
- If heated seat module C359A has not been previously disconnected, carry out the following steps:
- 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: 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.
- Disconnect: HVAC Module C2109A (without navigation) or C228A (with navigation).
- Ignition ON.
- Measure the voltage between heated seat module C359A-2, circuit CHS29 (WH/BU), harness side and ground.
Is any voltage present?
Yes
REPAIR the circuit. CLEAR the DTCs. TEST the system for normal operation.
DISCONNECT the battery ground cable.
CONNECT passenger seat side air bag module C339.
CONNECT driver seat side air bag module C3051.
REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
No
GO to N20.
N20 CHECK THE HEATED SEAT MODULE SWITCH REQUEST CIRCUIT FOR AN OPEN
- If heated seat module C359A has not been previously disconnected, carry out the following steps:
- 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: 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.
- Disconnect: HVAC Module C2109A (without navigation) or C228A (with navigation) (if not previously disconnected).
- Ignition OFF.
- For vehicles with navigation, measure the resistance between heated seat module C359A-2, circuit CHS29 (WH/BU), harness side and HVAC module C228A-5, circuit CHS29 (WH/BU), harness side.
- For vehicles without navigation, measure the resistance between heated seat module C359A-2, circuit CHS29 (WH/BU), harness side and HVAC module C2109A-18, circuit CHS29 (WH), harness side.
Is the resistance less than 5 ohms?
Yes
GO to N21.
No
REPAIR the circuit. CLEAR the DTCs. TEST the system for normal operation.
DISCONNECT the battery ground cable.
CONNECT passenger seat side air bag module C339.
CONNECT driver seat side air bag module C3051.
REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
N21 CHECK THE HEATED SEAT MODULE SWITCH REQUEST CIRCUIT FOR A SHORT TO GROUND
- If heated seat module C359A has not been previously disconnected, carry out the following steps:
- 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: 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.
- Disconnect: HVAC Module C2109A (without navigation) or C228A (with navigation) (if not previously disconnected).
- Measure the resistance between heated seat module C359A-2, circuit CHS29 (WH/BU), harness side and ground.
Is the resistance greater than 10,000 ohms?
Yes
GO to N22.
No
REPAIR the circuit. CLEAR the DTCs. TEST the system for normal operation.
DISCONNECT the battery ground cable.
CONNECT passenger seat side air bag module C339.
CONNECT driver seat side air bag module C3051.
REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
N22 CHECK THE HVAC MODULE OUTPUT
NOTICE: This pinpoint test step directs testing circuits using a back-probe method. Use the special back-probe tool specified in the tool list. Do not force test leads or other probes into connectors. Adequate care must be exercised to avoid connector terminal damage while ensuring that good electrical contact is made with the circuit or terminal. Failure to follow these instructions may cause damage to wiring, terminals, or connectors and subsequent electrical faults.
- Connect: HVAC Module C2109A (without navigation) or C228A (with navigation).
- Connect: Heated Seat Module C359A and C359B.
- Ignition ON.
- NOTE: The following measurement must be taken by back-probing heated seat module C359A.
NOTE: Voltage on circuit CHS29 (WH/BU) should drop momentarily when the driver heated seat button is pressed.
Measure and record the voltage between heated seat module C359A-2, circuit CHS29 (WH/BU), harness side and ground by carefully back-probing the heated seat module connector.
- Measure and record the voltage as directed above while pressing the driver heated seat button.
Is the voltage greater than 10 volts before pressing the driver heated seat button, then momentarily drops when the heated seat button is pressed?
Yes
INSTALL a new heated seat module. REFER to Heated Seat Module - Front . TEST the system for normal operation.
DISCONNECT the battery ground cable.
CONNECT passenger seat side air bag module C339.
CONNECT driver seat side air bag module C3051.
REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
No
If the voltage is greater than 10 volts but does not drop when the driver heated seat button is pressed, INSTALL a new HVAC module. TEST the system for normal operation.
If the voltage is less than 10 volts, INSTALL a new heated seat module. REFER to Heated Seat Module - Front . TEST the system for normal operation.
DISCONNECT the battery ground cable.
CONNECT passenger seat side air bag module C339.
CONNECT driver seat side air bag module C3051.
REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.