HandsFreeLink Control Unit
| DTC | Description | DTC type |
|---|---|---|
| B1775 | Microphone input/output short to power/open | Signal error |
| B1776 | Microphone input/output short to ground/open | Signal error |
| B1779 | HFL switch (HFL talk/HFL back buttons) circuit open/short | Signal error |
| B1780 | HFL switch (HFL talk/HFL back buttons) circuit short | Signal error |
| B1792 | HandsFreeLink control unit internal error | Internal error |
HANDSFREELINK DTC INDEX (B1775-B1792)
OnStar Control Unit ('05-06 models)
| DTC | Description | DTC type |
|---|---|---|
| B1400 | Communication bus line error (BUS-OFF) | Loss of communication |
| B1401 | OnStar control unit internal error (CPU error) | Internal error |
| B1402 | OnStar control unit internal error (EEPROM error) | Internal error |
| B1403 | GPS receiver error | Signal error |
| B1404 | Telephone module error | Signal error |
| B1405 | OnStar control unit lost communication with driver's MPCS unit (DOORSW message) | Loss of communication |
| B1406 | OnStar control unit lost communication with driver's MPCS unit (DRLOCKSW message) | Loss of communication |
| B1407 | OnStar control unit lost communication with driver's MPCS unit (ASLOCKSW message) | Loss of communication |
| B1408 | OnStar control unit lost communication with gauge control module (VSP/NE message) | Loss of communication |
| B1425 | OnStar control unit lost communication with SRS unit | Loss of (collision detection system line) communication |
| B1426 | OnStar switches circuit malfunction | Signal error |
| B1427 | Microphone circuit malfunction | Signal error |
| B1428 | GPS antenna circuit malfunction | Signal error |
| B1433 | Cellular phone antenna circuit malfunction | Signal error |
OnStar DTC INDEX (B1400-B1433)