Injector Circuit Malfunction - Cylinder 1
What does P0201 mean?
The P0201 code means the vehicle's onboard diagnostic system has detected: Injector Circuit Malfunction - Cylinder 1. This is a serious severity code.
Common Symptoms
- Check Engine Light on
- Misfire on cylinder 1
- Rough idle
- Power loss
- Fuel smell from exhaust
Probable Causes (Ranked by Likelihood)
- Open or short in cylinder 1 injector circuit Very High
- Failed cylinder 1 fuel injector High
- Damaged wiring or connector at cylinder 1 injector High
- PCM driver fault for cylinder 1 injector Moderate
Step-by-Step Diagnostic Procedure
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Identify cylinder 1 location on your engine.
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Plug a NOID light into the cylinder 1 injector connector. Crank the engine and observe flashing.
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If NOID flashes, the PCM driver is OK. Test the injector resistance (should be 11-17 ohms high-impedance).
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No NOID flash: check wiring from injector to PCM for breaks or shorts.
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Replace injector if resistance is out of spec or if it leaks fuel with no electrical pulse.
Frequently Asked Questions
Should I replace all injectors if one fails?
Not necessarily. If the injector failed due to contamination or electrical damage, replacing only the failed unit is fine. If the engine has very high mileage and poor maintenance history, a set replacement may be more cost-effective.