Circuit/System Testing

WARNING: This page is about a different car, the 2007 Pontiac G6. However, it is still accessible from the selected car via links, so may be relevant.

Ignition OFF, disconnect the EBCM harness connector at the brake fluid pressure sensor
With a DMM test for less than 5.0 ohms of resistance between the brake fluid pressure sensor low reference circuit terminal 1 and ground
- If greater than the specified range, with the DMM test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the EBCM
Ignition ON, with a DMM test for 4.4-5.6 volts between the brake fluid pressure sensor 5-volt reference circuit terminal 3 and ground
- If less than the specified range, with the DMM 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 the specified range, with the DMM test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the EBCM
With the DMM, verify the brake pressure sensor signal range is less than 4.4 volts
- If greater than the specified value, test the signal circuit terminal 2 for a short to voltage. If the circuit tests normal, replace the EBCM
Install a 3A fused jumper wire between the brake fluid pressure sensor signal circuit terminal 2 and the brake fluid pressure sensor 5-volt reference circuit terminal 3. With a DMM verify the voltage value is greater than 5.6 volts
- If less than the specified value, test the signal circuit terminal 2 for a 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 fluid pressure sensor