OBD-II Code P0265 — What It Means & How to Fix It

What Does This Error Mean?

P0265 means the Cylinder 2 fuel injector circuit is reading too high. The engine computer detected more voltage than expected on the circuit that controls Cylinder 2's injector. This usually means a short to power in the wiring, or the injector itself has a shorted coil. Cylinder 2 may be over-fueling, causing rich exhaust, rough running, or excessive fuel consumption. A shorted injector also risks damaging the ECM driver circuit — fix it promptly.

Affected Models

All vehicles 1996+
Common in Ford, GM, Toyota, Dodge vehicles
Common after wiring harness repairs done incorrectly
Seen frequently in vehicles with heat-damaged wiring near exhaust
Common in direct injection engines with carbon-fouled injectors

Common Causes

Short to power in the cylinder 2 injector control wiring
Shorted injector coil on cylinder 2 drawing excess current
Bridged connector pins at the cylinder 2 injector connector
Damaged harness section in contact with a battery positive wire
ECM driver circuit failure for cylinder 2 outputting excess voltage

How to Fix It

Scan for all codes and check if cylinder 2 also has a misfire code (P0302). A shorted injector on cylinder 2 can cause over-fueling and raw fuel in the exhaust, potentially triggering a misfire or catalyst codes.

Multiple injector high-codes across cylinders suggests a wiring harness issue, not individual injectors.
Inspect the cylinder 2 injector wiring for any section that's touching a power wire or battery cable. A wire rubbed through its insulation and resting against a positive circuit creates exactly this kind of short.

Focus on areas where wiring is routed near the battery, alternator, or fuse box.
Measure the resistance of the Cylinder 2 injector. Disconnect it from the harness and test across both terminals. A near-zero reading confirms a shorted injector coil.

Normal injector resistance is 12–17 ohms. Near-zero ohms means the coil windings have short-circuited internally.
Check the voltage at the cylinder 2 injector connector with the key on. If you read near battery voltage (12V) on the signal wire, there's a short to power in the harness or connector.

The injector signal wire should only show a brief switching voltage — not a constant high voltage.
After repairing the wiring or replacing the injector, clear all codes and use live scan data to verify that cylinder 2 injector pulse width has returned to normal. It should match the other cylinders at idle.

If the ECM driver circuit was damaged by the shorted injector, it may need professional repair before normal operation resumes.

When to Call a Professional

A confirmed wiring short that can't be found visually requires an automotive electrician with proper tools. If the short is traced to the ECM internal driver circuit, ECM repair or replacement is needed. Never replace the ECM without first confirming the wiring is clean — a shorted harness will destroy a new ECM just as quickly. ECM repairs typically cost $300–$1,500.

Frequently Asked Questions

Can a shorted Cylinder 2 injector damage other cylinders?

Not directly — but it can damage the ECM. The ECM has separate driver circuits for each injector. A shorted injector draws too much current and can burn out the ECM's driver circuit for that cylinder. Once the ECM driver fails, other affected repairs may be needed even after replacing the injector.

Is P0265 worse than P0264?

They're both serious, but in different ways. P0264 (low circuit) usually means the cylinder isn't firing — wasted fuel and potential catalytic converter damage. P0265 (high circuit) means over-fueling and potential ECM damage from excess current draw. Neither should be ignored — but a shorted injector (P0265) is arguably more urgent.

How much does it cost to fix P0265?

Wiring repair: $100–$350. Injector replacement: $150–$400 installed. Connector replacement: $50–$200. ECM driver circuit repair: $300–$1,200. Always replace the shorted injector before addressing any ECM damage — fixing the root cause first is essential.