For 1990-2009 cars only
The OnStar Communication Interface Module (CIM) monitors the GPS coax for a short to ground in the GPS antenna coax circuit.
DTC Parameters
| • | The CIM must be On. |
| • | Short to ground on GPS coax. |
| • | Test runs once every second. |
| • | Illuminate the Red OnStar telltale. |
Important: Do not perform an ohm's test on the circuit to the GPS antenna unless the coax is disconnected. Damage will results.
Diagnostic Aids
If the condition is suspected to be intermittent, moving the wires may help in duplicating the condition. Check the connections at the antenna.
