P0261 – Cylinder 1-8 Injector Circuit Low

The P0261 is a generic OBD-II code that indicates "Cylinder 1 Injector Circuit Low". This means there is an issue with the electrical circuit or wiring that controls the fuel injector for cylinder #1. While this code applies to most makes and models, the specific repair steps may vary slightly.

Can you keep driving with a P0261 code?

Although a vehicle with a P0261 code can often still be driven, it's best to diagnose and fix the issue promptly. Ignoring this code can result in reduced engine performance, increased emissions, rough idling or misfires in cylinder 1, and potentially costlier repairs down the road.

Parts involved

• Fuel injector #1
• Wiring harness and connectors for injector #1
• Powertrain Control Module (PCM)

Fuel injectors precisely spray fuel into the engine cylinders. They are controlled by the PCM which pulses the injectors on and off. Issues with the injector itself, the wiring, or rarely the PCM can trigger a P0261 code.

Common causes

1. Faulty fuel injector
2. Damaged wiring or loose/corroded connector to injector
3. Shorted injector solenoid coil
4. Faulty PCM (rare)

Diagnosing P0261 step-by-step:

1. Scan for codes, note freeze frame data
2. Visually inspect injector wiring and connectors
3. Test resistance of injector coil (should be 12-16 ohms)
4. Perform noid light test on injector
5. If injector fails tests, replace it, otherwise suspect wiring issue
6. Repair damaged wires, clean/replace corroded connector
7. Erase code and retest to verify fix

In most cases, this issue is caused by a loose/corroded electrical connector on the injector, a fouled injector (dirty or clogged), or a defective injector that needs replacement. Loose or corroded connectors are the most common cause of electrical faults.

Repair solutions:

• Replace faulty fuel injector
• Repair damaged injector wiring
• Clean injector electrical connector
• Replace injector pigtail connector
• Replace PCM (only if other causes ruled out)

Prevention:

• Use high quality fuel free of contaminants
• Have fuel injectors cleaned every 50,000-100,000 km (30,000-60,000 miles)
• Address any fuel system issues promptly

Cost of repair:

• Fuel injector: $75-300 USD / €70-280 EUR per injector
• Pigtail connector: $5-25 USD / €5-25 EUR
• Professional diagnosis and replacement labor: $75-150 USD / €70-140 EUR
• Total cost estimate: $150-500 USD / €140-470 EUR

Related issues:

Other cylinder injector circuit codes (P0262, P0264, etc.) can occur along with P0261. Misfires (P0301, P0302) and lean codes (P0171, P0174) are also common. If multiple injector codes are present, suspect an issue with the wiring harness or PCM.

Any trouble code related to a malfunctioning fuel injector is a serious issue that can affect how the engine runs. If ignored, it may lead to engine damage. Have the P0261 code diagnosed and repaired as soon as possible to keep your vehicle's engine in good running condition.

Frequently Asked Questions About P0261

What does the P0261 code mean?

The P0261 is a generic OBD-II code that indicates “Cylinder 1 Injector Circuit Low”. It means there is an issue with the electrical circuit or wiring that controls the fuel injector for cylinder #1.

What are the common symptoms of a P0261 code?

Common symptoms include:

• Check engine light illuminated
• Rough idle or misfires, especially in cylinder 1
• Reduced engine performance
• Increased fuel consumption

Can I keep driving with a P0261 code?

While a vehicle with a P0261 code can often still be driven, it’s best to diagnose and fix the issue promptly. Ignoring this code can result in further engine damage.

What are the common causes of a P0261 code?

Common causes include:

• Faulty fuel injector in cylinder 1
• Damaged wiring or loose/corroded electrical connector to the injector
• Shorted injector solenoid coil
• Faulty PCM (rare)

How do I diagnose a P0261 code?

Diagnostic steps include:

• Scan for codes and note freeze frame data
• Visually inspect injector wiring and connectors
• Test resistance of injector coil (should be 12-16 ohms)
• Perform a noid light test on the injector
• If the injector fails tests, replace it; otherwise, suspect a wiring issue

How do I fix a P0261 code?

After diagnosis, common fixes include:

• Replacing a faulty fuel injector
• Repairing damaged injector wiring
• Cleaning the injector electrical connector
• Replacing the injector pigtail connector
• Replacing the PCM (only if other causes are ruled out)

How much does it cost to repair a P0261 code?

Repair costs can vary but estimates are:

• Fuel injector: $75-300 per injector
• Pigtail connector: $5-25
• Professional diagnosis and replacement labor: $75-150
• Total cost estimate: $150-500

Can a P0261 code cause long-term engine damage if ignored?

Yes, ignoring a P0261 code can lead to incomplete combustion, increased emissions, catalytic converter damage, and potentially severe engine damage over time. Address the issue promptly.

Is a P0261 code specific to cylinder 1 or can it affect other cylinders?

The P0261 code is specific to the injector circuit for cylinder 1. However, similar codes exist for the other cylinders (e.g., P0264 for cylinder 2, P0267 for cylinder 3, etc.).

Can a P0261 code be caused by bad fuel?

Contaminated or poor-quality fuel can clog fuel injectors over time, potentially triggering a P0261 code. However, a fuel quality issue would likely affect multiple cylinders, not just cylinder 1.

Can a weak battery or charging system cause a P0261 code?

Unlikely. While low system voltage can cause a variety of issues, a weak battery or alternator would not typically trigger a cylinder-specific code like P0261.

Can a P0261 code be triggered by a vacuum leak?

No, a vacuum leak would not directly cause a P0261 code as this code is related to an electrical issue with the injector circuit. However, a major vacuum leak can cause running issues that might be confused with injector problems.

Can a blown fuse cause a P0261 code?

Yes, if the fuse that powers the fuel injectors is blown, it could trigger a P0261 code. Check the fuse box and replace any blown fuses as part of the diagnostic process.

Can a P0261 code be caused by a bad PCM?

It’s possible but rare. The Powertrain Control Module (PCM) controls the fuel injectors. A faulty PCM can cause injector issues, but this is much less common than a problem with the injector itself or its wiring.

Will disconnecting the battery clear a P0261 code?

Disconnecting the battery will clear the code from the PCM’s memory. However, if the underlying issue is not fixed, the code will likely return once the vehicle is driven again.

Can a P0261 code be caused by a bad mass airflow sensor?

No, a faulty mass airflow (MAF) sensor would not directly trigger a P0261 code. The MAF sensor measures air entering the engine and is not directly related to the injector circuits. However, a bad MAF sensor can cause drivability issues.

Can a P0261 code cause a vehicle to fail an emissions test?

Yes, a misfiring injector will cause incomplete combustion, which can lead to increased hydrocarbon emissions. This can cause a vehicle to fail an emissions or smog test.

How often should fuel injectors be cleaned to prevent issues like a P0261 code?

As a preventative measure, it’s a good idea to use fuel injector cleaner every 30,000 miles or so. Many people do this with every oil change. Keeping injectors clean can help prevent clogs and faults.

Can a P0261 code be caused by a bad fuel pump?

Unlikely. A faulty fuel pump would exhibit symptoms like hard starting, stalling, and lack of power under load. It would not normally trigger a cylinder-specific injector circuit code like P0261.

Is it safe to use fuel additives to clean injectors if I have a P0261 code?

If you suspect dirty injectors, it’s best to have them professionally cleaned or replaced. Over-the-counter fuel additives can help maintain clean injectors but are unlikely to fix one that is already faulty enough to trigger a code. Rely on professional diagnosis to determine the underlying cause before attempting any repairs.