Pinpoint Test G: The Heated Steering Wheel Does Not Operate/Does Not Operate Correctly
Heated Steering Wheel
Pinpoint Test G: The Heated Steering Wheel Does Not Operate/Does Not Operate Correctly
Refer to Wiring Diagram Set 128, Adjustable Steering Column for schematic and connector information Electrical Diagrams.
Normal Operation
When steering wheel heat is requested, the heated steering wheel temperature is maintained by the Heated Steering Wheel Module (HSWM) using a sensor in the steering wheel (integral to the steering wheel). The resistance of the sensor rises as the temperature falls and the resistance falls as the temperature rises. The resistance can vary from 3,384 ohms at 50°C (122°F) to 34,699 ohms at 0°C (32°F). The HSWM (Heated Steering Wheel Module) supplies a reference voltage and ground to the temperature sensor and monitors the voltage drop from the temperature sensor for controlling current flow to the heating element. The HSWM (Heated Steering Wheel Module) is designed to remain on, heating the steering wheel and maintaining temperature until switched OFF on the Front Display Interface Module (FDIM) or the ignition is turned OFF.
NOTE: On all vehicles, slow heating between the 10 o'clock and 2 o'clock steering wheel hand positions is considered normal. On vehicles equipped with wood inserts in the steering wheel, there is no heating elements located under the inserts.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Steering wheel
- Clockspring
- HSWM (Heated Steering Wheel Module)
PINPOINT TEST G : THE HEATED STEERING WHEEL DOES NOT OPERATE/DOES NOT OPERATE CORRECTLY
G1 CHECK THE HSWM (Heated Steering Wheel Module) DTCs
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self-Test- Heated Steering Wheel Module (HSWM).
Are any DTCs present?
Yes
REFER to the Heated Steering Wheel Module (HSWM) DTC Chart. Steering Wheel
No
GO to G2.
G2 CHECK THE HEATER ELEMENT TEMPERATURE SENSOR REFERENCE CIRCUIT FOR LOW RESISTANCE TO GROUND
- Ignition OFF.
- Disconnect: HSWM (Heated Steering Wheel Module) C2406.
- Measure the resistance between ground and HSWM (Heated Steering Wheel Module) C2406-5, circuit VHS73 (GN/BN), harness side.
Is the resistance greater than 10,000 ohms?
Yes
GO to G5.
No
GO to G3.
G3 CHECK THE HEATER ELEMENT TEMPERATURE SENSOR REFERENCE CIRCUIT FOR LOW RESISTANCE TO GROUND
- Depower the Supplemental Restraint System (SRS). Refer to Restraints and Safety Systems &/or Air Bag Systems.
- Remove the steering column shrouds to access the clockspring connectors. Refer to Steering Column Shroud .
- Disconnect: Clockspring C218A.
- Measure the resistance between ground and:
- HSWM (Heated Steering Wheel Module) C2406-5, circuit VHS73 (GN/BN), harness side.
- HSWM (Heated Steering Wheel Module) C2406-12, circuit RHS73 (BN/BU), harness side.
Are the resistances greater than 10,000 ohms?
Yes
GO to G4.
No
REPAIR circuit VHS73 (GN/BN) or RHS73 (BN/BU) for low resistance to ground. CONNECT clockspring C218A and HSWM (Heated Steering Wheel Module) C2406. REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
G4 CHECK THE HEATER ELEMENT TEMPERATURE SENSOR RESISTANCE
- Remove the driver air bag module.
- Disconnect: Clockspring C218B.
- Measure the resistance between ground and:
- clockspring C218B-1, steering wheel side.
- clockspring C218B-2, steering wheel side.
Are the resistances greater than 10,000 ohms?
Yes
INSTALL a new clockspring. REINSTALL the driver air bag module. CONNECT HSWM (Heated Steering Wheel Module) C2406. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
No
INSTALL a new steering wheel. REFER to Steering Wheel . REINSTALL the driver air bag module.
CONNECT HSWM (Heated Steering Wheel Module) C2406. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
G5 CHECK THE HEATER ELEMENT TEMPERATURE SENSOR AND CIRCUIT RESISTANCE
- Measure the resistance between HSWM (Heated Steering Wheel Module) C2406-5, circuit RHS73 (BN/BU), harness side and HSWM (Heated Steering Wheel Module) C2406-12, circuit VHS73 (GN/BN), harness side and compare to the table below.
Ambient Temperature Resistance 0-10°C (32-50°F) 18,754-34,699 ohms 10-20°C (50-68°F) 11,831-21,046 ohms 20-25°C (68-77°F) 9,500-13,149 ohms 25-30°C (77-86°F) 7,632-10,500 ohms 30-35°C (86-95°F) 6,173-8,482 ohms 35-40°C (95-104°F) 5,024-6,889 ohms 40-50°C (104-122°F) 3,384-5,630 ohms
Is the resistance within the specified values for the temperature?
Yes
GO to G8.
No
GO to G6.
G6 CHECK THE HEATER ELEMENT TEMPERATURE SENSOR CIRCUITS FOR A SHORT
- Depower the SRS (Supplemental Restraint System). Refer to Restraints and Safety Systems &/or Air Bag Systems.
- Remove the steering column shrouds to access the clockspring connectors. Refer to Steering Column Shroud .
- Disconnect: Clockspring C218A.
- Measure the resistance between HSWM (Heated Steering Wheel Module) C2406-5, circuit RHS73 (BN/BU), harness side and HSWM (Heated Steering Wheel Module) C2406-12, circuit VHS73 (GN/BN), harness side.
Is the resistance greater than 10,000 ohms?
Yes
GO to G7.
No
REPAIR circuit VHS73 (GN/BN) and RHS73 (BN/BU) for low resistance between them. CONNECT clockspring C218A and HSWM (Heated Steering Wheel Module) C2406. REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
G7 CHECK THE HEATER ELEMENT TEMPERATURE SENSOR RESISTANCE
- Remove the driver air bag module.
- Disconnect: Clockspring C218B.
- Measure the resistance between clockspring C218B-1, steering wheel side and clockspring C218B-2, steering wheel side and compare to the table below.
Ambient Temperature Resistance 0-10°C (32-50°F) 18,754-34,699 ohms 10-20°C (50-68°F) 11,831-21,046 ohms 20-25°C (68-77°F) 9,500-13,149 ohms 25-30°C (77-86°F) 7,632-10,500 ohms 30-35°C (86-95°F) 6,173-8,482 ohms 35-40°C (95-104°F) 5,024-6,889 ohms 40-50°C (104-122°F) 3,384-5,630 ohms
Is the resistance within the specified values for the temperature?
Yes
INSTALL a new clockspring. REINSTALL the driver air bag module. CONNECT HSWM (Heated Steering Wheel Module) C2406. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
No
INSTALL a new steering wheel. REFER to Steering Wheel . REINSTALL the driver air bag module.
CONNECT HSWM (Heated Steering Wheel Module) C2406. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
G8 CHECK THE HSWM (Heated Steering Wheel Module) CONNECTION
- Disconnect all the HSWM (Heated Steering Wheel Module) connectors.
- Inspect the HSWM (Heated Steering Wheel Module) connectors for:
- corrosion
- pushed-out terminals
- damaged terminals
- Connect and correctly seat all the HSWM (Heated Steering Wheel Module) and clockspring connectors.
- Ignition ON.
- Clear the DTCs.
- Enter the following diagnostic mode on the scan tool: Self-Test- Heated Steering Wheel Module (HSWM).
- Operate the heated steering wheel system and verify the concern is still present.
Is the concern still present?
Yes
INSTALL a new HSWM (Heated Steering Wheel Module). REFER to Heated Steering Wheel Module (HSWM) . TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. TEST the system for normal operation.