Pinpoint Test R: The Heated Seat is Inoperative - Driver
Seats
Pinpoint Test R: The Heated Seat is Inoperative - Driver
Refer to Wiring Diagram Set 119 (Fusion/Milan/MKZ, Fusion Hybrid, Milan Hybrid, MKZ Hybrid), Climate Controlled Seats for schematic and connector information. Diagrams By Number
Normal Operation
The heated seat module receives battery voltage. The HVAC module supplies a momentary ground signal to the heated seat module to request the system on/off. The heated seat module supplies voltage to the heater mats. The heated seat module monitors the heater mat temperature sensor. If the temperature sensor circuits open, the heated seat module will disable output voltage to the heater mat. The heated seat module control circuits are monitored by the HVAC module and will set a DTC if a circuit fault is detected.
The Front Controls Interface Module (FCIM) (with navigation), HVAC module and heated seat module must be communicating correctly for the system to operate correctly. PIDs are available to check heated seat switch operation in the FCIM (with navigation) and HVAC module (with and without navigation).
Normal heat cycle may require several minutes to initially warm the seat. The seat should be occupied to correctly test for normal operation. Temperature measuring devices do not provide an accurate method for testing heated seat operation as surface temperatures are subject to human and environmental characteristics. Correct testing requires heater mat resistance measurements which have tight tolerances affecting the length of time for the heater mats to reach maximum operating temperature.
- DTC B1030:12 (Left Front Seat Heater: Circuit Short To Battery) - If the driver seat control circuit from the HVAC module to the heated seat module is shorted to voltage, the DTC is set in the HVAC module.
- DTC B1030:14 (Left Front Seat Heater: Circuit Short To Ground or Open) - If the driver seat control circuit from the HVAC module to the heated seat module is shorted to ground or open, the DTC is set in the HVAC module.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Heater feed circuit short to battery, ground or open
- Sensor circuit short to battery, ground or open
- Heated seat switch stuck closed to ground
- Heater mat
- Heated seat module
- HVAC module
- FCIM (if equipped)
PINPOINT TEST R: THE HEATED SEAT IS INOPERATIVE - DRIVER
NOTE: If a seat equipped with a seat mounted side air bag is being serviced, the Supplemental Restraint System (SRS) must be depowered. Refer to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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 fault.
NOTE: The SRS must be fully operational and free of faults before releasing the vehicle to the customer.
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R1 CHECK HEATED SEAT OPERATION
- Start the engine.
- Verify the passenger heated seat is operational.
- Is the passenger heated seat operational?
Yes
GO to R2.
No
GO to Symptom Chart to diagnose the heated seats are inoperative - driver and front passenger or the heated seat is inoperative/does not operate correctly - passenger. Symptom Related Diagnostic Procedures
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R2 CHECK HEATED SEAT INDICATOR ILLUMINATION
- Verify system indicator illumination.
- Do the driver heated seat indicators illuminate or flash and then turn off?
Yes
GO to R7.
No
Vehicles with navigation, GO to R3.
Vehicles without navigation, GO to R4.
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R3 RETRIEVE THE FCIM DTCs
- Enter the following diagnostic mode on the scan tool: Self Test - FCIM.
- Are any FCIM DTCs retrieved?
Yes
For all FCIM DTCs, REFER to the Master DTC Chart in Information and Entertainment Systems Testing and Inspection.
No
GO to R4.
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R4 RETRIEVE THE HVAC MODULE DTCs
- Enter the following diagnostic mode on the scan tool: Self Test - HVAC Module.
- Are any HVAC module DTCs retrieved?
Yes
If DTC B1030:12, GO to R18.
If DTC B1030:14, GO to R19.
For any other HVAC module DTCs, REFER to the HVAC Module DTC Chart. HVAC Module DTC Chart
No
For vehicles with navigation, GO to R5.
For vehicles without navigation, GO to R6.
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R5 MONITOR THE DRIVER HEATED SEAT (CC_SW_D_HSEATS) PID AND CHECK INPUTS
- Enter the following diagnostic mode on the scan tool: DataLogger - FCIM - PIDs: CC_SW_D_HSEATS.
- Monitor the FCIM PID while pushing the driver heated seat button.
- Do the PID states agree with the switch button positions?
Yes
GO to R6.
No
INSTALL a new FCIM. REFER to Information and Entertainment Systems Service and Repair. TEST the system for normal operation.
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R6 MONITOR THE DRIVER HEATED SEAT (CC_SW_D_HSEATS) PID AND CHECK INPUTS
- Enter the following diagnostic mode on the scan tool: DataLogger - HVAC Module - PIDs: CC_SW_D_HSEATS.
- Monitor the HVAC module PID while pushing the driver heated seat button.
- Do the PID values agree with the switch button positions?
Yes
The fault is intermittent, CHECK for causes of the intermittent fault. INSPECT the connectors, terminals and wiring. ATTEMPT to recreate the fault by flexing the wire harness and operating the system. CHECK the electrical connectors for corrosion, poor pin contact or pushed-out pins. REPAIR any intermittent concerns found and TIGHTEN any loose connector pins. REPEAT the self-test. CLEAR the DTCs. CHECK the system for normal operation.
No
INSTALL a new HVAC module. TEST the system for normal operation.
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R7 CHECK FOR VOLTAGE TO THE HEATED SEAT MODULE
- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in the General Procedures portion of Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Driver Seat Side Air Bag Module C327.
- Disconnect: Passenger Seat Side Air Bag Module C313.
- Disconnect: Heated Seat Module C3304B.
- 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, Mounting and Cables Battery Disconnect.
- Measure the voltage between heated seat module C3304B-1, circuit SBP18 (YE/RD) harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to R8.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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R8 CHECK THE TEMPERATURE SENSOR OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: Heated Seat Module C3304A.
- Disconnect: Driver Seat Cushion Heater Mat C364.
- Ignition ON.
- Measure the voltage between heated seat module C3304A-3, circuit VHS26 (VT), harness side and ground.
- Is any voltage present?
Yes
REPAIR the circuit. GO to R11 to check the temperature sensor for damage. If OK, TEST the system for normal operation. If not OK, INSTALL a new driver seat cushion heater mat. REFER to Seat Cushion Cover - Front Seat Cushion Cover - Front.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
No
GO to R9.
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R9 CHECK THE TEMPERATURE SENSOR OUTPUT CIRCUIT FOR AN OPEN AND SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between:
- heated seat module C3304A-3, circuit VHS26 (VT), harness side and rear seat cushion heater mat C364-3, circuit VHS26 (VT), harness side.
- heated seat module C3304A-3, circuit VHS26 (VT), harness side and ground.
- Is the resistance less than 5 ohms between C3304A-3 and C364-3, and greater than 10,000 ohms between C3304A-3 and ground?
Yes
GO to R10.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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R10 CHECK THE TEMPERATURE SENSOR RETURN CIRCUIT FOR AN OPEN
- Measure the resistance between heated seat module C3304A-12, circuit RHS05 (YE/VT), harness side and driver seat cushion heater mat C364-4, circuit RHS05 (YE/VT), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to R11.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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R11 CHECK THE TEMPERATURE SENSOR FOR AN OPEN
- Measure the resistance between rear heated seat cushion C364 pin 3 and pin 4, component side.
- Is the resistance between 300 ohms and 300,000 ohms?
Yes
GO to R12.
No
INSTALL a new cushion heater mat. REFER to Seat Cushion Cover - Front Seat Cushion Cover - Front. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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R12 CHECK THE HEATER MAT OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition ON.
- Measure the voltage between heated seat module C3304B-4, circuit CHS02 (YE/BU), harness side and ground.
- Is any voltage present?
Yes
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
No
GO to R13.
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R13 CHECK THE HEATER MAT OUTPUT CIRCUIT FOR AN OPEN AND SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between:
- heated seat module C3304B-4, circuit CHS02 (YE/BU), harness side and cushion heater mat C364-1, circuit CHS02 (YE/BU), harness side.
- heated seat module C3304B-4, circuit CHS02 (YE/BU), harness side and ground.
- Is the resistance less than 5 ohms between C3304B-4 and C364-1, and greater than 10,000 ohms between C3304B-4 and ground?
Yes
GO to R14.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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R14 CHECK THE HEATER MAT RESISTANCE
- Connect: Driver Seat Backrest Heater Mat C365.
- Connect: Driver Seat Cushion Heater Mat C364.
- Measure the resistance between heated seat module C3304B-4, circuit CHS02 (YE/BU), harness side and ground.
- Is the resistance between 1.2 and 4.0 ohms?
Yes
GO to R21.
No
GO to R15.
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R15 CHECK THE CUSHION HEATER MAT FOR AN OPEN
- Disconnect: Driver Seat Cushion Heater Mat C364.
- Measure the resistance between driver seat cushion heater mat C364 pins 1 and 2, component side.
- Is the resistance between 0.6 and 2.0 ohms?
Yes
GO to R16.
No
INSTALL a new driver seat cushion heater mat. REFER to Seat Cushion Cover - Front Seat Cushion Cover - Front. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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R16 CHECK THE CIRCUIT BETWEEN THE CUSHION HEATER MAT AND BACKREST HEATER MAT FOR AN OPEN AND SHORT TO GROUND
- Disconnect: Driver Seat Backrest Heater Mat C365.
- Measure the resistance between:
- seat cushion heater mat C364-2, circuit CHS11 (VT/GN), harness side and seat backrest heater mat C365-1, circuit CHS11 (VT/GN), harness side.
- seat cushion heater mat C364-2, circuit CHS11 (VT/GN), harness side and ground.
- Is the resistance less than 0.5 ohm?
Yes
GO to R17.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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R17 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 0.6 and 2.0 ohms?
Yes
REPAIR circuit GD126 (BK/WH) for an open. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
No
INSTALL a new driver seat backrest heater mat. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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R18 CHECK HEATED SEAT MODULE SWITCH INPUT CIRCUIT FOR SHORT TO VOLTAGE
- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in the General Procedures portion of Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Passenger Seat Side Air Bag Module C313.
- Disconnect: Heated Seat Module C3304A.
- Disconnect: HVAC Module C2356A.
- 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, Mounting and Cables Battery Disconnect.
- Ignition ON.
- Measure the voltage between heated seat module C3304A-2, circuit CHS29 (WH/BU), harness side and ground.
- Is any voltage present?
Yes
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
No
INSTALL a new HVAC module. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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R19 CHECK THE HEATED SEAT MODULE SWITCH INPUT CIRCUIT FOR AN OPEN
- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in the General Procedures portion of Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Passenger Seat Side Air Bag Module C313.
- Disconnect: Heated Seat Module C3304A.
- Disconnect: HVAC Module C2356A.
- 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, Mounting and Cables Battery Disconnect.
- Measure the resistance between heated seat module C3304A-2, circuit CHS29 (WH/BU), harness side and HVAC module C2356A-5, circuit CHS29 (WH/BU), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to R20.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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R20 CHECK THE HEATED SEAT MODULE SWITCH INPUT CIRCUIT FOR A SHORT TO GROUND
- Measure the resistance between heated seat module C3304A-2, circuit CHS29 (WH/BU), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
INSTALL a new heated seat module. REFER to Heated Seat Module Heated Seat Module. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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R21 CHECK THE HVAC MODULE OUTPUT
- Connect: Heated Seat Module C3304A and C3304B.
- Ignition ON.
- NOTE: The following measurement must be taken by back-probing heated seat module C3304A.
- NOTE: Voltage on circuit CHS29 (WH/BU) should drop momentarily when the driver heated seat control button is pressed.
- Measure the voltage between heated seat module C3304A-2, circuit CHS29 (WH/BU), harness side and ground by back-probing heated seat module connector. Press the driver heated seat button on the HVAC module and note the voltage.
- Is the voltage greater than 10 volts before pressing the driver heated seat control button, then momentarily drops when the heated seat control button is pressed?
Yes
INSTALL a new heated seat module. REFER to Heated Seat Module Heated Seat Module. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
No
If voltage is greater than 10 volts but did not drop when the driver heated seat button was pressed, INSTALL a new HVAC module. TEST the system for normal operation.
If voltage is less than 10 volts, INSTALL a new heated seat module. REFER to Heated Seat Module Heated Seat Module. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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