P0263⛽ Fuel injection / cylinder balanceStop and fix promptly

P0263: Cylinder 1 Contribution/Balance (Meaning, Causes, Fixes)

Reviewed 2026-10-25 · Based on 2 cited source(s)

What P0263 means

The engine computer (PCM) watches how much the crankshaft speeds up during each cylinder's power stroke. OBD-Codes.com explains that when one cylinder adds less acceleration than the rest, the PCM sets a contribution/balance code for that cylinder, and P0263 is the one for cylinder 1. OBD-Codes.com says this points to a fuel-related problem in that cylinder, and that a purely electrical injector fault would normally set a separate circuit high or low code (such as P0201, P0261 or P0262) instead. RepairPal describes it more generally: the PCM has detected that cylinder 1 is not contributing enough to keep the engine running properly. The code is generic to OBD-II vehicles, but search interest shows it comes up a lot on diesels such as Ford 6.0L and 6.7L Power Stroke trucks, and test details vary by manufacturer, so check technical service bulletins (TSBs) for your vehicle.

Severity: can I keep driving?

Stop and fix promptly

Get it diagnosed soon. RepairPal rates P0263 'Urgent', meaning it can cause severe damage, and OBD-Codes.com says it should be fixed at your earliest convenience to prevent damage. A cylinder that isn't pulling its weight can run rough and lose power. If the check engine light is flashing, the engine shakes badly, or you smell raw fuel or see heavy smoke, keep driving to a minimum and have it checked. Fuel systems run under high pressure, especially on diesels, so don't open fuel lines with the engine running and let the engine cool before working near it.

Common symptoms

Likely causes

Roughly most to least common, based on the sources below. Your vehicle may differ.

  1. Dirty, clogged or dribbling cylinder 1 fuel injector, for example from a contaminated injector inlet filter (OBD-Codes.com says lack of fuel to cylinder 1 is the most likely cause)
  2. Failed cylinder 1 fuel injector
  3. Corroded terminals or pushed-out pins in the injector connector
  4. Wiring problem (listed by RepairPal)
  5. Failed fuel injection control module, FICM, on vehicles that have one (listed by RepairPal; not mentioned by OBD-Codes.com)
  6. Internal engine problem in cylinder 1 (listed by RepairPal)
  7. Engine computer (PCM) failure (listed by RepairPal)

Diagnostic steps you can do

⚠ Before you start

Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.

  1. Read all stored codes. Note any injector circuit codes such as P0201, P0261 or P0262 or misfire codes such as P0301, since they help narrow down the cause.
  2. Look up technical service bulletins for your year, make and model, as OBD-Codes.com recommends.
  3. Inspect the cylinder 1 injector connector and the harness side for corrosion, bent or pushed-out pins. Fix any damage and add dielectric grease before reconnecting.
  4. On a gasoline engine, OBD-Codes.com suggests listening to the injector with a long screwdriver (handle to your ear) while the engine runs. A steady ticking means it is firing; no ticking means no power or a dead injector.
  5. Clear the code and drive. If the rough running and the code come back after the connector checks out, the injector likely needs cleaning or replacement.

Typical fixes

Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.

🛠 When to call a pro

  • OBD-Codes.com notes a power-balance test (pulling one spark plug wire at a time and watching the RPM drop) can find weak cylinders, and says all cylinders should be within 5 percent of each other
  • OBD-Codes.com says a supply voltage check at the injector should show battery voltage; no voltage means an open circuit between the injector and the fuel pump relay
  • The sources differ on causes: OBD-Codes.com focuses on the injector and its connector, while RepairPal also lists the FICM, internal engine failure, wiring and the PCM
  • Diesel engines (such as Ford Power Stroke) have high-pressure injection systems; injector testing and replacement on those is best left to a shop with the right scan tool
  • The code returns after injector cleaning or replacement, or other cylinders also set contribution/balance codes

Where to buy

Plain search links. Always match parts to your exact year, make, model and engine.

OBD2 scanners on Amazon Parts at Advance Auto Parts catalog at RockAuto

FAQs

Can I drive with P0263?

Only as much as you need to. RepairPal rates it 'Urgent', and OBD-Codes.com says to fix it at your earliest convenience to prevent damage. If the engine shakes badly or the check engine light flashes, limit driving and get it checked.

Is P0263 always a bad injector?

No, but it's the most common cause. OBD-Codes.com says a lack of fuel to cylinder 1, from a clogged, dribbling or failed injector, is the most likely cause. RepairPal also lists wiring, a fuel injection control module (FICM), internal engine problems and the PCM, so check the connector and test before buying parts.

What's the difference between P0263 and P0201?

P0201 is an electrical fault in the cylinder 1 injector circuit. P0263 means cylinder 1 is making less power than the others, which OBD-Codes.com says usually points to a fuel delivery problem rather than a wiring short or open.

Why does P0263 come up so often on Ford Power Stroke diesels?

Our sources don't give a reason specific to Ford diesels. Searches for P0263 do often mention the 6.0L and 6.7L Power Stroke, and RepairPal lists FICM failure as a possible cause, which applies to engines that use a fuel injection control module. Check for TSBs for your truck.

Sources

  1. OBD-Codes.com: P0263 Cylinder 1 Contribution/Balance (Don Bowman, ASE)
  2. RepairPal: P0263 OBD-II code (rated Urgent)

Last reviewed 2026-10-25. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.