P0289 – Cylinder 10 Injector Circuit High

P0289 is an OBD-II trouble code that points to a problem with the fuel injector circuit for cylinder 10. While not every engine has ten cylinders, this code shows up most often on larger V8 and V10 engines in trucks, vans, and performance vehicles. When this code sets, your engine computer is seeing an electrical or performance issue with that specific injector. You might notice rough running, misfires, poor fuel economy, or a flashing check engine light. The good news: with a systematic approach, you can usually track it down and fix it without guesswork.

What Does P0289 Mean?

P0289 stands for “Cylinder 10 Injector Circuit High.” Your ECU (engine control unit) constantly monitors the electrical signal going to each fuel injector. When it sees higher-than-expected voltage or resistance in the injector circuit for cylinder 10, it stores P0289 and may turn on the check engine light.

In plain terms, the computer is telling you that the injector for cylinder 10, or the wiring that controls it, isn’t behaving normally. That can mean a wiring fault, a failing injector, a bad connection, or in rare cases, an ECU issue.

Quick Reference

• Code: P0289
• Meaning: Cylinder 10 Injector Circuit High
• Main area: Fuel injector and wiring for cylinder 10
• Common symptoms: Misfire, rough idle, loss of power, poor MPG
• Risk level: Moderate to high if driven for long
• Typical fixes: Wiring repair, injector replacement, connector cleaning

Real-World Example / Field Notes

In the shop, I usually see P0289 on heavy-duty trucks or vans with V10 engines, often used for towing or commercial work. A common pattern: the owner complains of a rough running engine under load and a flashing check engine light on hills. Scan shows P0289 plus a misfire code on cylinder 10. Many times, the harness to the back cylinders has rubbed through on a bracket or heat shield, causing high resistance in the injector circuit. Fixing the damaged wiring and securing the harness properly often restores smooth operation without needing a new injector.

Symptoms of P0289

• Check engine light illuminated, sometimes flashing during heavy acceleration.
• Rough idle that feels like the engine is shaking or “loping.”
• Engine misfire, especially noticeable under load or at higher RPM.
• Loss of power and sluggish acceleration, particularly when towing or climbing hills.
• Poor fuel economy due to inefficient combustion and misfires.
• Fuel smell from the exhaust or tailpipe, sometimes accompanied by black smoke.
• Hard starting or longer crank time, especially when the engine is cold.
• Engine vibration felt through the steering wheel, seat, or pedals.

Common Causes of P0289

Most Common Causes

• Faulty injector on cylinder 10 – Internal electrical failure, short, or high resistance in the injector coil.
• Damaged wiring harness – Chafed, melted, or corroded wires to injector 10 causing high circuit resistance.
• Loose or corroded connector – Poor contact at the injector plug or intermediate connectors in the harness.
• Poor ground or power supply – Shared power or ground circuits for the injectors having high resistance or intermittent contact.

Less Common Causes

• ECU/PCM driver fault – The internal injector driver circuit in the engine computer failing or going out of spec.
• Aftermarket tuning or wiring mods – Incorrectly installed performance chips, piggyback systems, or remote start wiring interfering with the injector circuit.
• Water intrusion – Moisture in connectors or harnesses, especially in vehicles that see off-road or severe weather use.
• Previous repair damage – Pinched wires or poorly repaired splices from earlier engine or transmission work.

Diagnosis: Step-by-Step Guide

You’ll want a basic set of tools: an OBD-II scan tool (preferably with live data and Mode $06), a digital multimeter, basic hand tools, and if possible, a noid light or injector tester. A wiring diagram for your specific vehicle is also very helpful.

1. Confirm the code and check for companions. Scan the vehicle and verify P0289 is present. Look for related misfire codes (like P03XX) or other injector codes. Multiple injector codes may point to a shared power or ground problem.
2. Inspect cylinder 10 location. Identify which cylinder is #10 based on the manufacturer’s firing order and bank layout. On V10s, cylinder 10 is usually at the back, often harder to access.
3. Visual inspection of wiring and connector. With the engine off, inspect the injector 10 connector and harness. Look for broken locks, corrosion, green or white deposits, oil saturation, melted insulation, or rubbing against brackets or exhaust components.
4. Wiggle test. Start the engine and gently move the harness and connector for injector 10. If the engine stumbles or the code resets while moving the wiring, you likely have an intermittent connection or broken wire.
5. Check injector resistance. Disconnect injector 10 and measure resistance across the injector terminals with a multimeter. Compare the reading to spec and to a known-good injector on another cylinder. A significantly higher or lower reading indicates a bad injector.
6. Verify power and ground at the connector. With the key on (engine off), use a test light or multimeter to confirm you have proper voltage on the power feed and good ground or ECU control signal on the other terminal, depending on your system design.
7. Use a noid light or injector tester. Plug a noid light into the injector connector and crank or run the engine. A strong, regular flash shows the ECU is commanding the injector; weak or erratic flashing may point to wiring or ECU driver issues.
8. Check live data and Mode $06. Some scanners let you see individual cylinder misfire counts and injector pulse data. High misfire counts on cylinder 10 that follow the injector or wiring when swapped confirm the fault location.
9. Perform a swap test (if practical). On some engines, you can swap injector 10 with another cylinder. If the code and misfire move with the injector, the injector is bad. If they stay on cylinder 10, the issue is wiring or ECU related.
10. Inspect ECU and common harness points. If wiring and injector test good, inspect connectors at the ECU and any intermediate junctions. Look for bent pins, corrosion, or water damage.

Pro tip: On high-mileage trucks and vans, always gently tug on each wire at the injector connector. It’s common to find a wire broken inside the insulation right at the crimp, which can look perfect from the outside but cause intermittent high resistance.

Possible Fixes & Repair Costs

Once you’ve pinpointed the cause, the repair is usually straightforward: replace the faulty injector, repair damaged wiring, or clean and tighten connectors. In rare cases, you may need an ECU replacement or reflash. Typical repair costs vary widely by vehicle and access: a basic wiring repair might run $100–$250, a single injector replacement often falls in the $200–$600 range parts and labor, and ECU replacement or programming can range from $500 to over $1,200. Labor rates, engine layout, and parts quality (OEM vs aftermarket) all affect the final bill.

• Replace cylinder 10 injector – Install a new or high-quality reman injector and new seals; clear codes and retest.
• Repair or replace damaged wiring – Cut out corroded or broken sections, solder and heat-shrink new wire, and re-route away from heat and sharp edges.
• Clean and secure connectors – Use electrical contact cleaner, repair or replace loose terminals, and ensure connectors lock firmly.
• Fix shared power/ground issues – Clean and tighten ground points, repair blown fuses or damaged fuse box terminals, and verify voltage drop is within spec.
• ECU/PCM repair or replacement – If confirmed faulty, replace or send out for professional repair, then program with the correct software and immobilizer data.

Can I Still Drive With P0289?

You can usually drive a short distance with P0289, but it’s not something you want to ignore. If the engine is misfiring, running rough, or the check engine light is flashing, you should avoid heavy acceleration, towing, or highway speeds. Driving gently to a shop is often fine, but extended driving with a misfire can overheat and damage the catalytic converters, wash down cylinder walls with fuel, and cause more expensive repairs. If the engine feels very rough or unsafe, have it towed instead.

What Happens If You Ignore P0289?

Ignoring P0289 can turn a relatively simple injector or wiring repair into a much bigger problem. Continuous misfires dump unburned fuel into the exhaust, which can destroy catalytic converters and oxygen sensors. Over time, you can also cause excessive wear on pistons, rings, and spark plugs, and risk stalling at inconvenient or unsafe times. Addressing the code early almost always saves money and prevents collateral damage.

Last updated: January 22, 2026

Vehicles Commonly Affected by P0289

P0289 shows up most often on larger engines with more than eight cylinders. You’ll commonly see it on Ford and Dodge/Ram V10 trucks and vans, motorhomes built on heavy-duty chassis, and some commercial or fleet vehicles with multi-cylinder gasoline engines. It can also appear on certain high-performance or specialty vehicles with 10-cylinder layouts. While the basic meaning of the code is the same across manufacturers, wiring colors, injector locations, and diagnostic procedures can vary, so always reference service information for your specific make and model.