Information Bus: Testing and Inspection

CCD BUS FAILURE
The CCD data bus can be monitored using the DRB III scan tool. However, it is possible for the data bus to pass all tests since the voltage parameters will be in "range" and false signals are being sent. There are essentially 12 "hard failures" that can occur with the CCD data bus:
- Bus Shorted to Battery
- Bus Shorted to 5 Volts
- Bus Shorted to Ground
- Bus (+) Shorted to Bus (-)
- Bus (-) and Bus (+) Open
- Bus (+) Open
- Bus (-) Open
- No Bus Bias
- Bus Bias Level Too High
- Bus Bias Level Too Low
- No Bus Termination
- Not Receiving Bus Messages Correctly

Refer to the appropriate diagnostic information for details on how to diagnose these faults using a DRB III scan tool.

BUS FAILURE VISUAL SYMPTOM DIAGNOSIS
The following visible symptoms or customer complaints, alone or in combination, may indicate a CCD data bus failure:
- Airbag Indicator and Malfunction Indicator Lamp (MIL) Illuminated
- Instrument Cluster Gauges (All) Inoperative
- No Compass Mini-Trip Computer (CMTC) Operation (if equipped)