Circuit/System Testing
WARNING: This page is about a different car, the 2008 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the harness connector at the EBCM.
- Retest for current DTCs. DTC U2099 should remain current.
- If the DTC becomes history, replace the EBCM.
- Ignition OFF, disconnect the X 3 harness connector at the BCM.
- Test for infinite resistance between the serial data communication enable circuit terminal 19 and ground.
- If less than infinite resistance, repair the enable circuit for a short to ground.
- If all circuits tests normal, replace the BCM.