P0263 Cylinder 1 Contribution / Balance

OBD-II Trouble Code - P0263 - Datasheet

P0263 - Cylinder number 1, contribution / balance malfunction

What does trouble code P0263 mean?

This Diagnostic Trouble Code (DTC) is a generic transmission code, which means it applies to OBD-II equipped vehicles. Although general, specific repair steps may differ depending on the brand / model.

OBD II DTC P0263 is described as Cylinder 1 Contribution / Balance. Essentially, this code states that the number one cylinder in the ignition order is experiencing a fuel problem.

It is also a common code, meaning it is common to all manufacturers. The link is the same, however the manufacturer of a particular model may have encountered a faulty part or an installation error.

Always refer to the online technical service bulletins (TSB) for your specific year and make the vehicle. Find the appropriate TSB and the manufacturer's recommended repair procedure.

The powertrain control module (PCM) monitors the power output from each cylinder by comparing the acceleration or increase in crankshaft speed during the stroke of each cylinder.

DTC P0263 will set when one or more cylinders deliver less power than the other cylinders.

While the PCM is performing this test to determine if the fuel injector is working properly, an auto mechanic can perform a similar test to determine internal engine problems. By pulling out one spark plug at a time while the engine is running, he notes the drop in the rpm of each cylinder.

All cylinders must be within 5 percent of each other. Any cylinder showing less RPM drop will require repair. Both tests are similar in that they both compare engine speed.

This is a problem that needs to be addressed as early as possible to prevent possible damage.

Cross section of a typical automotive fuel injector (courtesy of WikipedianProlific):

Symptoms

Symptoms displayed for the P0263 code may include:

• Check if the engine light is on and a code P0263 is set.
• Rough idle
• Falling fuel economy
• The Check Engine light will come on , and the code will be set to the ECM memory and freeze frame.
• Engine may run rough and low power.
• The engine will misfire causing jolts or jerks, as well as uneven idling.
• Engine may not have enough power during acceleration while the misfire is active.

Causes of the P0263 code

In my experience, this code means less power being produced in cylinder number one. An electrical problem will set a code for a high or low voltage situation for this injector.

The most likely cause is a lack of fuel in cylinder number one. The injector could completely fail or a small amount of fuel flows out of it, and not the usual conical jet. This could be due to dirt or contamination of the injector inlet filter.

• Possible defect of the electrical connector on the fuel injector due to corrosion of the terminals or pushing out of the pins.
• Dirty or clogged fuel injector
• Defective fuel injector
• Cylinder number one injector is not injecting enough fuel or not injecting fuel at all.
• Injector number one is open or shorted (other DTCs will be present).
• Fuel pressure is low or low in volume due to a clogged fuel filter or faulty pump.
• The compression in the first cylinder is low due to problems with the rocker arms, pushrods, cam, rings or cylinder head gasket.
• The injector o-ring is leaking compression.

Diagnostic and repair procedure

• Inspect the electrical connector on the fuel injector. Inspect the side of the seat belt for corrosion or ejection pins. Check the nozzle for bent pins. Repair any defects, add dielectric grease to the connector terminals, and reinstall the connector.
• Start the engine. Use a long screwdriver with the handle to your ear and the blade to the injector, and listen for the characteristic “ticking” noise to indicate that it is working. The absence of noise means that either it is not receiving power or the injector is out of order.
• Using a wire probe on a voltmeter, check the red power wire at the injector. It should show the battery voltage. If there is no voltage, then there is an open in the wiring between the injector and the fuel pump relay. If voltage is present and the injector is working, it is likely clogged and needs cleaning.
• Purchase a “direct flush fuel injector kit” from an auto parts store. It consists of a cylinder with an injector cleaner and a hose connector leading to the fuel rail.
• Remove the fuel pump fuse from the driver's side fender main fuse / relay box.
• Start the engine and let it run until the fuel pressure drops and it stalls.
• Clamp the fuel return line with a needle vise.
• Remove the shredder valve from the fuel pump inspection hole on the fuel rail. Install the hose to the test port.
• Screw a can of injector cleaner onto the hose and wait a few seconds for the cleaner to pressurize the fuel rail. Start the engine and run the vacuum cleaner until it stalls.
• Remove the purifier hose from the test port and reinstall the schrader valve. Remove the vise clamps from the return line and install the fuel pump fuse.
• Erase the DTC and reset the PCM with a conventional code reader.
• Start the engine. If rough idle continues and the code returns, replace the fuel injector.

How does a mechanic diagnose a P0263 code?

• Scans codes and documents freeze frame data to confirm problem.
• Clears engine and ETC codes to see if the problem returns
• Starts an electrical injector self-test.
• Checks fuel pressure and volume according to specifications
• Performs crankcase pressure test
• Checks compression in cylinders and repairs if necessary
• Checks the o-rings and nozzle seals, then replaces the nozzle if necessary.

Common Mistakes When Diagnosing Code P0263?

• Code validation error returned after scanning and deleting code
• Lack of fuel pressure volume check during diagnostics before injector replacement

How serious is the P0263 code?

A misfired cylinder can cause the engine to run lean on the failed cylinder if it is an injector and cause black smoke to be emitted from the engine if the cylinder has low compression.

What repairs can fix code P0263?

• Replacing the injector and injector gaskets
• Replacing the fuel filter and fuel pump
• Engine repair for low compression in the cylinder

Additional comments to consider regarding code P0263

Code P0263 is triggered when the crankshaft sensor is not receiving crankshaft acceleration from cylinder #1 power stroke, indicating that the cylinder is not contributing to engine power. The injector may also be shorted or open, which will cause additional codes, which will be accompanied by a P0263 code indicating an injection failure.

What is P0263 Engine Code [Quick Guide]

Need more help with your p0263 code?

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NOTE. This information is provided for informational purposes only. It is not intended to be used as a repair recommendation and we are not responsible for any action you take on any vehicle. All information on this site is protected by copyright.