Circuit/System Testing

Ignition ON.
Verify that DTC U152B is not set.
- If the DTC is set
  Refer to Diagnostic Trouble Code (DTC) List - Vehicle
- Go to next step: If the DTC is not set
Ignition OFF and all vehicle systems OFF, disconnect the X2 harness connector at the X85 Steering Wheel Air Bag Coil. It may take up to 2 minutes for all vehicle systems to power down.
Test for less than 10 Ω between the ground circuit terminal 1 and ground.
- If 10 Ω or greater
1. Ignition OFF.
2. Test for less than 2 Ω in the ground circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, repair the open/high resistance in the ground connection.
- Go to next step: If less than 10 Ω
Ignition ON.
Verify a test lamp illuminates between the ignition circuit terminal 9 and ground.
- If the test lamp does not illuminate and the circuit fuse is good
1. Ignition OFF.
2. Test for less than 2 Ω in the ignition circuit end to end.
  - If less than 2 Ω, verify the fuse is OK and there is voltage at the fuse. Refer to Power Mode Mismatch .
  - Go to next step: If 2 Ω or greater
3. Verify the in-line fuse is OK and there is voltage at the fuse.
  - If the in-line fuse is blown, replace the K32 Steering Wheel Heating Control Module.
  - If the in-line fuse is OK, repair the open/high resistance in the circuit.
- If the test lamp does not illuminate and the circuit fuse is open
1. Ignition OFF.
2. Test for infinite resistance between the ignition circuit and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
  - If infinite resistance, replace the K32 Steering Wheel Heating Control Module.
- Go to next step: If the test lamp illuminates
Ignition OFF, connect the X2 harness connector at the X85 Steering Wheel Air Bag Coil. Disconnect the harness connector at the S70A Steering Wheel Control Switch - Left Lower.
Test for less than 10 Ω between the ground circuit terminal 7 and ground.
- If 10 Ω or greater
1. Ignition OFF.
2. Test for less than 2 Ω in the ground circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, repair the open/high resistance in the ground connection.
- Go to next step: If less than 10 Ω
Ignition ON.
Test for B+ between the signal circuit terminal 5 and ground.
- If less than B+
1. Ignition OFF, disconnect the in-line harness connector at the K32 Steering Wheel Heating Control Module.
2. Test for infinite resistance between the control circuit and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
  - Go to next step: If infinite resistance
3. Test for less than 2 Ω in the control circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, replace the K32 Steering Wheel Heating Control Module.
- Go to next step: If B+
Ignition OFF, disconnect the in-line harness connector at the E15 Steering Wheel Heater.
Test for less than 10 Ω between the ground circuit terminal 4 and ground.
- If 10 Ω or greater
1. Ignition OFF.
2. Test for less than 2 Ω in the ground circuit end to end.
  - If less than 2 Ω, repair the open/high resistance in the circuit.
  - If 2 Ω or greater, replace the K32 Steering Wheel Heating Control Module.
- Go to next step: If less than 10 Ω
Test for 1.5 - 3.0 Ω between the signal terminal 3 and the ground terminal 4 at the E15 Steering Wheel Heater.
- If not within the specified range
  Replace the E15 Steering Wheel Heater.
- Go to next step: If within the specified range
Test for 9 - 11k Ω between the control circuit terminal 2 and the ground terminal 1 on the E15 Steering Wheel Heater.
- If not within the specified range
  Replace the E15 Steering Wheel Heater.
- Go to next step: If within the specified range
Replace the K32 Steering Wheel Heating Control Module.