Circuit/System Testing
WARNING: This page is about a different car, the 2012 GMC Yukon, 2012 Chevrolet Tahoe, and 2012 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the harness connector at the steering angle sensor.
- Wait for 60 seconds, test for less than 5.0 Ω between the low reference circuit terminal 2 and ground.
- If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the EBCM.
- Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 1 and ground.
- If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the EBCM.
- If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the EBCM.
- Verify the scan tool Steering Wheel Sensor Signal parameter is greater than 4.5 V.
- If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the EBCM.
- Install a 3A fused jumper wire between the signal circuit terminal 6 and the 5 V reference circuit terminal 1. Verify the scan tool SWPS Signal A parameter is greater than 4.5 V.
- If less than the specified range, test the signal circuit terminal for a short to ground or an open/high resistance. If the circuit tests normal, replace the EBCM.
- Verify the scan tool Digital SWPS Phase A parameter is High.
- If not the specified parameter, test the signal circuit terminal 3 for a short to ground. If the circuit tests normal, replace the EBCM.
- Install a 3A fused jumper wire between the signal circuit terminal 3 and the low reference circuit terminal 2. Verify the scan tool Digital SWPS Phase A parameter is Low.
- If not the specified parameter, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the EBCM.
- Verify the scan tool Digital SWPS Phase B parameter is High.
- If not the specified parameter, test the signal circuit terminal 4 for a short to ground. If the circuit tests normal, replace the EBCM.
- Install a 3A fused jumper wire between the signal circuit terminal 4 and the low reference circuit terminal 2. Verify the scan tool Digital SWPS Phase B parameter is Low.
- If not the specified parameter, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the EBCM.
- Ignition ON, at the steering angle sensor connector harness, test for 6.8-11 V between the signal circuit terminal 5 and ground.
- If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the EBCM.
- If greater than the specified range, test the appropriate signal circuit for a short to voltage. If the circuit tests normal, replace the EBCM.
- If the circuits test normal, replace the steering angle sensor.
NOTE:
When measuring voltage, the voltage values are based on a battery charge of 12.5 V and the steering wheel is in the center position.