Diagnostic Fault Information
WARNING: This page is about a different car, the 2006 Buick LaCrosse and 2006 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.
Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
IMPORTANT:
A condition with the powertrain (PT) relay will set multiple DTCs. The DTCs listed in the table will only set if a condition exists with the PT relay.
DTC P0685, P0686, P0687, P0689 or P0690
| Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
|---|---|---|---|---|---|
| B+ Supply Voltage - Coil | P0685 | P0685 | P0685 | - | - |
| B+ Supply Voltage - Switch | - | P0689 | P0689 | P0690 | - |
| Relay Control Circuit | P0686 | P0685 | P0685 | P0687 | P0685 |
| Ignition 1 Voltage Circuit | - | P0689 | P0689 | P0690 | - |