C0505moderate severityChassis
Transfer Case Position Sensor Circuit
on 2005 GMC Envoy 5.3L V8 · 4WD
What this code means
Malfunction in the sensor that reports the current transfer case range position.
Symptoms
- 4WD indicator not showing correct mode
- Service 4WD light
- Transfer case may not shift
- Unknown drive mode selected
Common causes
- Faulty position sensor
- Sensor wiring damage
- Transfer case not fully engaged in any position
- Sensor contaminated with fluid
Diagnostic steps
- Read transfer case position with scan tool
- Command mode change and watch sensor response
- Inspect sensor wiring
- Check transfer case fluid level and condition
- Test sensor resistance or voltage
Repair notes
Replace transfer case position sensor. Check fluid condition.
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C0021
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C0022
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C0026
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