Circuit/System Testing
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
- The PPS pressure sensor is not serviced separately. The PPS replacement with the PPS pressure sensor must be serviced as a complete unit.
- When removing connectors, inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected component/connector:
- The PPS pressure sensor
- The PPS module
- The PPS pressure sensor wiring harness connector
- The PPS module wiring harness connector
- Ignition OFF, disconnect the harness connector at the PPS pressure sensor and inspect the component and harness sides for damage or corrosion.
- If damage or corrosion is found, repair or replace as necessary.
- Ignition ON, test for 4.5-5.5 volts between the voltage reference circuit terminal A and ground.
- If less that the specified range, test the voltage reference circuit for open/high resistance or a short to ground. If the circuit tests normal, replace the PPS.
- If greater that the specified range, test the voltage reference circuit for a short to voltage. If the circuit tests normal, replace the PPS.
- Ignition OFF, remove the AIR BAG BATT Fuse. Test for less than 2.0 ohms between low reference terminal C and ground.
- If greater than the specified range, test the low reference circuit for open/high resistance. If the circuit tests normal, replace the PPS.
- Ignition OFF, disconnect the harness connector at the PPS module.
- Test for infinite resistance between the signal circuit terminal B and ground.
- If less than the specified value, test the signal circuit for a short to ground.
- Ignition ON, test for less than 1 volt between the signal circuit terminal B and ground.
- If greater than the specified range, test the signal circuit for a short to voltage.
- Test for less than 1 ohm in the signal circuit between PPS module terminal 6 and PPS sensor terminal B.
- If greater than the specified range, test the signal circuit for open/high resistance. If the circuit tests normal, replace the PPS.
- If all circuits test normal, replace the PPS which includes the pressure sensor.
IMPORTANT:
IMPORTANT:
The AIR BAG BATT Fuse that supplies B+ voltage must be removed to ensure the PPS module is inactive. An active PPS module may cause inaccurate resistance readings.