Parts
$15–80 per injector
P0201 — Injector Circuit Malfunction — Cylinder 1
STOPIs it safe to drive? Do not drive with a confirmed injector circuit failure — a dead injector causes a misfire that can destroy a catalytic converter in minutes and may indicate a wiring fault that could cause further damage.
What P0201 means
The ECU detected an electrical fault in the fuel injector circuit for cylinder 1. This can be an open circuit, a short to ground, or a short to voltage in the injector wiring or the injector itself.
Most likely causes (in order)
- Failed fuel injector (internal open or short, $15–80 each)
- Open circuit in the injector wiring — especially at the connector which vibrates and corrodes
- Short to ground in the injector signal wire
- Damaged wiring harness near the injector (heat, chafing)
- Faulty PCM injector driver (rare, but injectors can spike voltage and damage ECU drivers)
Symptoms you might notice
- Cylinder 1 misfire (usually sets P0301 simultaneously)
- Rough idle
- Loss of power
- Possible popping or backfire
- Rich or lean condition depending on fault type
What to check first
Measure injector resistance directly at the injector connector (disconnected): most port injectors measure 11–16 ohms (high-impedance); some low-impedance injectors measure 2–5 ohms. An open (infinite) or shorted reading confirms a bad injector. If resistance is good, the problem is in the wiring — check for power at the injector (should see battery voltage on one wire) and the PCM-controlled ground pulse on the other.
Repair cost & difficulty
Labor
0.5–2.0 hr
Difficulty
Moderate