Circuit/System Testing
WARNING: This page is about a different car, the 2007 GMC Sierra and 2007 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the 3 way harness connector at the brake booster vacuum sensor.
- Test for less than 1.0 ohm of resistance between the low reference circuit terminal 2 and ground.
- If greater than 1.0 ohm, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the EBCM.
- Ignition ON, test for 4.5-5.3 volts between the 5-volt reference circuit terminal 3 and ground.
- If less than 4.5 volts, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the EBCM.
- If greater than 5.3 volts, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the EBCM.
- Test for 4.5-5.3 volts between the 5-volt reference circuit terminal 3 and the signal circuit terminal 1.
- If less than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the EBCM.
- If greater specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the EBCM.
- If all circuits test normal, test or replace the brake booster vacuum sensor.