U1005 08 (CU AMPS - OnStar)

U1005 08

GPS Antenna Circuit, Open/Short Circuit

Fault symptom
- "On Star System Malfunction. Contact Service." shown on SID.

On-board diagnosis

Type of diagnosis:
- Continuous

Enable criteria:
- Ignition ON.
- Battery voltage must be between 9 - 16 V.
- No starter motor cranking.

Fault criteria:
- The resistance value of the antenna circuit is more/less than 288 ohm due to an open circuit/shorting to ground/B+.

Checking the wiring harness
- Jiggle the wiring harness at several points to detect intermittent breaks or short circuits. Check also the connector for oxidation or loose pins.

Diagnostic help
- Check that the following MIs/Campaigns have been carried out before starting fault diagnosis:

US Market
- MI No. 391-2394 - Customer Satisfaction Campaign 15421 - Update of OnStar system.
- MI No. 391-2409 - Customer Satisfaction Campaign 15424 - Update of OnStar system.

CA Market
- MI No. 391-2410 - Customer Satisfaction Campaign 15421 - Update of OnStar system.
- MI No. 391-2408 - Customer Satisfaction Campaign 15424 - Update of OnStar system.