FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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No Bus Bias

Test 1 - 3:




Test 4 - 8:




Test 9 - 11:




SYMPTOM
NO BUS BIAS

TEST NOTE
This symptom is diagnosed using the test BUS (+) & (-) OPEN.

POSSIBLE CAUSES
- Defective DRB/bias out of range
- CCD fused B(+) circuit voltage> 10
- CCD bus (+) circuit open
- CCD bus (-) circuit open
- CCD ignition OFF
- Open ground ckt/ no bus bias
- CCD fused ignition output circuit voltage> 10
- CCD BCM bias out of range
- Defective BCM-no bus bias
- Defective BCM-BUS(+)(-) open