Code C1780: Steering Sensor Input Fault
- Perform CVRSS system check. See CVRSS SYSTEM CHECK . After performing CVRSS system check, go to next step.
- If Code C1781 is set, go to applicable code for diagnosis. See CODE DESCRIPTION table under SELF-DIAGNOSTICS under DIAGNOSIS & TESTING. If Code C1781 is not set, go to next step.
- Turn ignition on, with engine. Center steering wheel and verify front wheels are straight. Using scan tool, monitor RSS DATA RS D15. If voltage is 2-3 volts, go to step 14 . If voltage is less than 2 volts or more than 3 volts, go to next step.
- Turn ignition off. Center steering wheel and verify front wheels are straight. Disconnect steering sensor connector. Using DVOM, measure resistance between 5-volt reference circuit (Gray wire) and ground circuit (Orange/Black wire) of steering sensor connector (component side). See WIRING DIAGRAMS . If resistance is 8000-12,000 ohms, go to next step. If resistance is less than 8000 or more than 12,000 ohms, go to step 17 .
- Using DVOM, measure resistance between steering signal circuit (Light Blue wire) and ground circuit (Orange/Black wire) of steering sensor connector (component side). If resistance is 4000-6000 ohms, go to next step. If resistance is less than 4000 or more than 6000 ohms, go to step 17 .
- Check for steering sensor misalignment. If steering sensor is misaligned, go to step 15 . If steering sensor is not misaligned, go to next step.
- Disconnect 24-pin CVRSS control module connector C2. Check continuity between the following circuits of CVRSS control module harness connector C2 and ground. See WIRING DIAGRAMS
.
- 5-volt reference circuit (Gray wire).
- Steering signal circuit (Light Blue wire).
- Ground circuit (Orange/Black wire).
If continuity does not exist on all circuits, go to next step. If continuity exists on any circuit, go to step 11 .
- Check for opens in 5-volt reference circuit (Gray wire), steering signal circuit (Light Blue wire), and ground circuit (Orange/Black wire). If open is present on any circuit, go to step 10 . If all circuits are okay, go to next step.
- Turn ignition on, with engine off. Check for short to voltage in 5-volt reference circuit (Gray wire), steering signal circuit (Light Blue wire), and ground circuit (Orange/Black wire). If voltage is present on any circuit, go to step 12 . If voltage is not present on any circuit, go to step 13 .
- Repair open in affected circuit.
- Repair short to ground in affected circuit.
- Repair short to voltage in affected circuit.
- Turn ignition off. Reinstall/reconnect all components/connectors. Clear codes. Drive vehicle faster than 50 MPH for more than 15 seconds. Display CVRSS codes. If Code C1780 is set, go to step 18 . If Code C1780 is not set, see NOTES ON INTERMITTENTS under DIAGNOSIS & TESTING.
- Using scan tool, monitor RSS DATA RS D15 while rotating steering wheel. See Fig 1 . If steering sensor output voltage is as specified, go to step 16 . If steering sensor output voltage is not as specified, go to step 18 .
- Realign steering sensor. See STEERING AUTOCENTER under ADJUSTMENTS.
- Check for intermittent short to ground, short to voltage or open in 5-volt reference circuit (Gray wire), steering signal circuit (Light Blue wire), and ground circuit (Orange/Black wire). Repair as necessary.
- Turn ignition off. Replace steering sensor. Perform steering autocenter adjustment. See STEERING AUTOCENTER under ADJUSTMENTS.
- Turn ignition off. Replace CVRSS control module. Reinstall/reconnect all components/connectors. Install scan tool. Turn ignition on, with engine off. Calibrate NEW CVRSS control module. See CALIBRATING CVRSS CONTROL MODULE under ADJUSTMENTS.