Circuit/System Testing
WARNING: This page is about a different car, the 2008 Pontiac G5 and 2008 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the harness connector at the brake booster vacuum sensor.
- Test for less than 1.0 ohm of resistance between the low reference circuit terminal 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 4.8-5.2 volts between the 5-volt reference circuit terminal and ground.
- If less than 4.8 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 5.2 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 and the signal circuit terminal.
- 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.
- Install a 3 A fused jumper wire at the signal circuit terminal. Toggle the jumper wire between the low reference circuit terminal and the 5-volt reference circuit terminal. Verify the scan tool Brake Pressure Sensor Input parameter toggles between 0.2-3.2 volts.
- If the specified parameter, does not toggle between the minimum and maximum values test the signal circuit for a short to voltage, short to ground or an open/high resistance. If the circuit tests normal, replace the EBCM.
- If all circuits test normal, test or replace the brake booster vacuum sensor.