P0262 — Cylinder 1 Injector Circuit High

What exactly does P0262 mean?

P0262 means the powertrain controller detected abnormally high voltage in the cylinder 1 injector circuit. The fault may involve the injector, its connector, the wiring, or the controller's injector driver.

Is P0262 always caused by a bad cylinder 1 injector?

No. An open harness, corroded connector, high-resistance terminal, or failed injector driver can produce the same P0262 condition, so circuit testing is required before replacing the injector.

Can the vehicle be driven with P0262 active?

It should be driven only cautiously and preferably not at all if cylinder 1 is misfiring. Continued operation with substantial unburned fuel can damage the catalytic converter.

How is P0262 cleared after the repair?

After repairing the injector or its circuit, clear the stored codes with an OBD scanner, road-test the vehicle, and scan again. P0262 should not return if the repair restored normal injector operation.

When your engine control unit detects that the voltage on the cylinder 1 fuel injector circuit sits above its normal operating range, it stores diagnostic trouble code P0262. This specific code belongs to the powertrain family and points directly at a problem with how the first cylinder receives its portion of fuel. The ECU constantly watches each injector circuit while the engine runs, comparing actual voltage readings against factory-programmed expectations. When the signal stays anomalously high — essentially stuck near battery voltage instead of the expected pulsed ground signal — the module logs P0262 after a set number of drive cycles.

Modern engines meter fuel with remarkable precision through electromagnetic injectors that spray atomized fuel directly into the intake port or combustion chamber. Each injector receives a ground pulse from the ECU while battery voltage feeds the other side of the circuit. On inline engines, cylinder numbering starts at the front (belt end) and counts backward. V-configuration engines vary by manufacturer, so consulting your specific firing-order diagram prevents confusion during diagnosis. The "circuit high" condition in P0262 indicates the ECU sees voltage on the signal line that should normally drop to near zero during injector operation — a clear sign of a short to power, an open ground path, or a failed component pulling the circuit high.

The module captures freeze frame data alongside P0262, recording RPM, engine load, coolant temperature, vehicle speed, and other sensor readings the instant the fault occurred. This snapshot gives technicians a reliable starting point for recreating the exact conditions that triggered the code. Understanding these parameters matters because intermittent issues often surface only under specific operating conditions.

Common symptoms of P0262

• Rough idle with noticeable engine hesitation
• Noticeable loss of power, especially under acceleration or load
• Strong fuel odor, particularly in more severe cases
• Fuel economy noticeably worse than normal
• Illuminated Check Engine warning lamp

What causes P0262?

• Signal wire to the cylinder 1 injector shorted to battery positive
• Open or damaged ground return circuit for cylinder 1 injector
• Failed cylinder 1 injector internally shorted and pulling the signal high
• Faulty fuel rail pressure sensor or its wiring harness
• Malfunctioning fuel pressure regulator
• Intake manifold vacuum leaks disrupting mixture ratio
• Clogged, leaking, or dirty fuel injectors
• Weak fuel pump or severely restricted fuel filter
• Contaminated or wrong specification fuel in the tank

How to diagnose P0262

1. Connect an OBD2 scanner and confirm P0262 is stored in the ECU memory. Save the freeze frame data immediately — it reveals engine operating conditions when the fault first appeared and guides your test strategy.
2. Pull all stored and pending codes. Related codes often expose the true root cause, such as fuel pressure or sensor issues that may have triggered P0262 as a secondary fault. Check manufacturer TSB databases for your make and model — many injector circuit codes have known factory remedies or calibration updates.
3. Perform a thorough visual inspection of the cylinder 1 injector wiring harness and connector. Look for damaged insulation, corroded terminals, chafing from contact with hot engine components, or loose connections that could interrupt proper circuit operation.
4. With the cylinder 1 injector disconnected, probe the harness-side signal terminal using a multimeter. A reading near battery voltage confirms a short to power in the wiring. If voltage drops to normal levels when the injector is unplugged, the injector itself has failed internally.
5. Measure fuel rail pressure at idle and under vacuum load, comparing results against factory specifications. Low pressure suggests pump or filter issues; erratic pressure points toward a faulty regulator.
6. Review short-term and long-term fuel trim data while monitoring live sensor values. Sustained high trim values indicate the ECU is compensating for an overly lean mixture, while other patterns reveal whether the problem stems from injector, pressure, or air metering issues.
7. Clear the code, complete a drive cycle that reproduces the freeze frame conditions (same RPM, load, temperature range), and verify P0262 does not return. Pending codes may require multiple drive cycles to fully clear.

How to fix P0262

Begin diagnosis with the least expensive and most frequently encountered culprits before committing to major component replacement:

• Replace the fuel pump — $400–$900
• Clean or replace fuel injectors — $200–$800
• Replace the fuel filter — $80–$200
• Replace the fuel pressure regulator or sensor — $150–$450

How much does it cost to fix P0262?

Total repair expense hinges entirely on which component triggered P0262 in your specific vehicle. Parts and labor estimates below assume independent shop rates in the United States.

• Replacing the fuel pump runs $400–$900, typically the highest ticket item.
• Injector cleaning or replacement costs $200–$800 depending on whether you can clean existing injectors or need new units.
• Fuel filter replacement is the most affordable option at $80–$200.
• Pressure regulator or sensor replacement falls between $150–$450 depending on vehicle architecture.

Across all possible repair paths, fixing P0262 generally costs between $80 and $900. Proper diagnosis before purchasing parts is essential — the most expensive scenario rarely represents the most likely cause.

Can you drive with P0262?

Proceed with caution. Faults triggering P0262 can produce stalling, hesitation during acceleration, and poor throttle response that creates hazardous situations in traffic. Severe cases risk running an overly rich or lean mixture that damages catalytic converter components. Avoid long trips or sustained high-load operation until the underlying cause receives proper diagnosis and repair.

Related OBD2 codes

• P0200: Injector Circuit Malfunction
• P0201: Injector Circuit Malfunction - Cylinder 1
• P0202: Injector Circuit Malfunction - Cylinder 2
• P0203: Injector Circuit Malfunction - Cylinder 3
• P0204: Injector Circuit Malfunction - Cylinder 4
• P0205: Injector Circuit Malfunction - Cylinder 5