Pinpoint Test C: The Heated Seat is Inoperative/Does Not Operate Correctly - Driver
Seats
Pinpoint Tests
Pinpoint Test C: The Heated Seat is Inoperative/Does Not Operate Correctly - Driver
Refer to Wiring Diagram Set 119 (Escape/Mariner, Escape Hybrid/Mariner Hybrid), Climate Controlled Seats for schematic and connector information. Diagrams By Number
Normal Operation
Voltage is supplied from Smart Junction Box (SJB) circuit CBP43 to the driver heated seat relay coil. When the heated seat switch button is pressed, the HVAC module supplies ground to the driver heated seat relay coil on circuit CHS29. When the relay is energized, battery voltage is supplied from SJB circuit SBP18 to the driver heater mats on circuit CHS11. The heater mats are directly connected to ground circuit GD182 completing the electrical circuit to heat the seat.
- The engine must be running (except Hybrid, turn the ignition on).
- The HVAC module must be communicating correctly.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Heated seat relay
- Heater mat
- HVAC module
PINPOINT TEST C: THE HEATED SEAT IS INOPERATIVE/DOES NOT OPERATE CORRECTLY - DRIVER
NOTE: The air bag warning indicator illuminates when the correct Restraints Control Module (RCM) fuse is removed and the ignition 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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C1 CHECK FOR HEATED SEAT INDICATOR ILLUMINATION
- Start the engine (except Hybrid, turn the ignition ON).
- Press the driver heated seat button to activate the heated seat.
- Does the indicator illuminate?
Yes
GO to C2.
No
VERIFY the climate control system is operating correctly. REFER to Climate Control System - General Information and Diagnostics Testing and Inspection or Climate Control System - General Information and Diagnostics - Hybrid Testing and Inspection to diagnose the inoperative climate control system.
If the climate control system is operating correctly, GO to C14.
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C2 RETRIEVE HVAC MODULE DTCs
NOTE: The engine must be running (except Hybrid, turn the ignition on).
- Enter the following diagnostic mode on the scan tool: Self Test - HVAC Module.
- Are any DTCs present?
Yes
If DTC B12AB or B1030:12 is present, GO to C3.
If DTC B12AC or B1030:14 is present, GO to C4.
For all other HVAC Module DTCs, REFER to the HVAC Module DTC Chart for diagnosis. Diagnostic Trouble Code Tests and Associated Procedures
No
GO to C8.
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C3 CHECK THE DRIVER HEATED SEAT REQUEST CIRCUIT FOR A 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: Driver Seat Side Air Bag C367.
- Disconnect: Driver Safety Belt Buckle Pretensioner C3201.
- Disconnect: HVAC Module C2357A or C2356B (C2356A Hybrid).
- Disconnect: Driver Heated Seat Relay C3253.
- 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 driver heated seat relay C3253-3, CHS29 (WH/BU), harness side and ground.
- Is any voltage present?
Yes
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat safety belt buckle pretensioner C3201 and driver seat side air bag C367.
REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
No
GO to C14.
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C4 CHECK THE DRIVER HEATED SEAT REQUEST CIRCUIT FOR A SHORT TO GROUND
- 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 C367.
- Disconnect: Driver Safety Belt Buckle Pretensioner C3201.
- Disconnect: Driver Heated Seat Relay C3253.
- Disconnect: HVAC Module C2357A or C2356B (C2356A Hybrid).
- Measure the resistance between driver heated seat relay C3253-3, circuit CHS29 (WH/BU), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to C5.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat safety belt buckle pretensioner C3201 and driver seat side air bag C367.
REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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C5 CHECK FOR VOLTAGE TO THE DRIVER HEATED SEAT RELAY COIL
- 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 driver heated seat relay C3253-1, circuit CBP43 (GY), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to C6.
No
VERIFY Smart Junction Box (SJB) fuse 43 (10A) is OK. If OK, REPAIR the circuit for an open. If not OK, Refer to the Wiring Diagrams to identify the possible causes of the circuit short. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation. Diagrams By Number
DISCONNECT the battery ground cable. CONNECT driver seat safety belt buckle pretensioner C3201 and driver seat side air bag C367.
REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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C6 CHECK THE DRIVER HEATED SEAT REQUEST CIRCUIT FOR AN OPEN
- Ignition OFF.
- For vehicles equipped with manual temperature control, measure the resistance between driver heated seat relay C3253-3, circuit CHS29 (WH/BU), harness side and HVAC module C2357A-1, circuit CHS29 (WH/BU), harness side.
- For Hybrid vehicles, measure the resistance between driver heated seat relay C3253-3, circuit CHS29 (WH/BU), harness side and HVAC module C2356A-5, circuit CHS29 (WH/BU), harness side.
- For vehicles equipped with automatic temperature control, measure the resistance between driver heated seat relay C3253-3, circuit CHS29 (WH/BU), harness side and HVAC module C2356B-6, circuit CHS29 (WH/BU), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to C7.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat safety belt buckle pretensioner C3201 and driver seat side air bag C367.
REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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C7 CHECK THE DRIVER HEATED SEAT RELAY FOR AN OPEN
- Install a test relay in the driver heated seat relay C3253.
- Start the engine (except Hybrid, turn the ignition ON).
- Press the driver heated seat button to activate the heated seat.
- Is DTC B12AC or B1030:14 present on-demand during self-test?
Yes
GO to C14.
No
INSTALL a new driver heated seat relay. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat safety belt buckle pretensioner C3201 and driver seat side air bag C367.
REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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C8 CHECK FOR VOLTAGE TO THE DRIVER HEATED SEAT RELAY
- 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 C367.
- Disconnect: Driver Safety Belt Buckle Pretensioner C3201.
- Disconnect: Driver Heated Seat Relay C3253.
- 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:
- driver heated seat relay C3253-5, circuit SBP18 (YE/RD), harness side and ground.
- driver heated seat relay C3253-1, circuit CBP43 (GY), harness side and ground.
- Are the voltages greater than 10 volts?
Yes
GO to C9.
No
VERIFY Smart Junction Box (SJB) fuses 18 (20A) and 43 (10A) are OK. If OK, REPAIR the circuit(s) for an open. If not OK, Refer to the Wiring Diagrams to identify the possible causes of the circuit short. TEST the system for normal operation. Diagrams By Number
DISCONNECT the battery ground cable. CONNECT driver seat safety belt buckle pretensioner C3201 and driver seat side air bag C367.
REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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C9 CHECK THE HEATER CIRCUIT FOR VOLTAGE
- Connect: Driver Heated Seat Relay C3253.
- Disconnect: Driver Backrest Heater Mat C3283.
- Start the engine (except Hybrid, turn the ignition ON).
- Press the driver heated seat switch on and measure the voltage between driver cushion heater mat C3283-2, circuit CHS11 (VT/GN), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to C11.
No
GO to C10.
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C10 CHECK THE DRIVER HEATED SEAT RELAY
- Ignition OFF.
- Install a test relay in the driver heated seat relay C3253.
- Start the engine (except Hybrid, turn the ignition ON).
- Press the driver heated seat switch on and measure the voltage between driver cushion heater mat C3283-2, circuit CHS11 (VT/GN), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
INSTALL a new heated seat relay. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat safety belt buckle pretensioner C3201 and driver seat side air bag C367.
REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
No
DISCONNECT the test relay and GO to C11.
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C11 CHECK THE HEATER CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: Driver Heated Seat Relay C3253.
- Measure the resistance between driver heated seat relay C3253-4, circuit CHS11 (VT/GN), harness side and driver cushion heater mat C3283-2, circuit CHS11 (VT/GN), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to C12.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat safety belt buckle pretensioner C3201 and driver seat side air bag C367.
REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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C12 CHECK THE HEATER GROUND CIRCUIT FOR AN OPEN
- Measure the resistance between driver cushion heater mat C3283-1, circuit GD182 (BK/GY), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
GO to C13.
No
REPAIR the circuit. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat safety belt buckle pretensioner C3201 and driver seat side air bag C367.
REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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C13 CHECK THE BACKREST HEATER MAT FOR AN OPEN
- Disconnect: Driver Backrest Heater Mat Electrical Connector.
- Measure the resistance between driver backrest heater mat electrical connector pins 1 and 2, component side.
- Is the resistance between 0.8 and 1.5 ohms?
Yes
INSTALL a new cushion heater mat. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat safety belt buckle pretensioner C3201 and driver seat side air bag C367.
REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
No
INSTALL a new backrest heater mat. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat safety belt buckle pretensioner C3201 and driver seat side air bag C367.
REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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C14 CHECK FOR CORRECT HVAC MODULE OPERATION
- Ignition OFF.
- Disconnect and inspect all HVAC Module connectors for:
- corrosion.
- pushed out terminals.
- damaged terminals.
- Connect and correctly seat all the HVAC module connectors.
- 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 (if previously disconnected). Refer to Battery, Mounting and Cables Battery Disconnect.
- Start the engine (except Hybrid, turn the ignition ON).
- Enter the following diagnostic mode on the scan tool: Self Test - HVAC Module.
- Is the concern still present or any DTCs present?
Yes
INSTALL a new HVAC module. REFER to Climate Control Service and Repair. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat safety belt buckle pretensioner C3201 and driver seat side air bag C367. (if previously disconnected).
REPOWER the SRS (if previously depowered). REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
No
The system is working correctly at this time. the concern may have been caused by module connections.
CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat safety belt buckle pretensioner C3201 and driver seat side air bag C367. (if previously disconnected).
REPOWER the SRS (if previously depowered). REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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