Injector Circuit High - Cylinder 8
The P0285 code means the vehicle's onboard diagnostic system has detected: Injector Circuit High - Cylinder 8. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $150 - $600 (parts and labor)
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Common Symptoms
- Check Engine Light on
- No fuel to cylinder 8
- Engine misfire and rough running
- Reduced power
Probable Causes (Ranked by Likelihood)
- Open circuit in cylinder 8 injector wiring Very High
- Failed injector (open coil) High
- Disconnected connector Moderate
- PCM driver open Low
Step-by-Step Diagnostic Procedure
-
Measure injector resistance. Infinite ohms = open coil.
-
Check connector.
-
Test wiring continuity.
-
Swap injectors to confirm.
Frequently Asked Questions
Can an injector coil fail suddenly?
Yes, injector coils can fail open without warning, causing an immediate misfire on that cylinder.
Is P0285 a safety concern?
Not immediately dangerous, but the misfire should be repaired promptly to prevent catalytic converter damage.
Do all V8s use the same injectors?
No, injector flow rate, resistance, and connector style vary by engine. Always match the injector to your specific engine.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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