P0206 – Injector Circuit/Open Cylinder 6

P0206 is an OBD-II trouble code that points to a problem with the fuel injector circuit on cylinder 6. When this code sets, your engine computer has detected an electrical fault—either too much resistance, a short to power or ground, or no control of the injector at all. You may notice rough running, misfires, poor fuel economy, or a check engine light that won’t go away. In this guide, you’ll learn what P0206 means, common causes, symptoms, how a mechanic diagnoses it, and what it usually costs to repair.

What Does P0206 Mean?

P0206 stands for “Injector Circuit Malfunction – Cylinder 6.” Your ECU (engine control unit) controls each fuel injector by rapidly switching the ground side of the circuit on and off. With P0206, the ECU sees an abnormal voltage or current on the cylinder 6 injector control circuit.

This doesn’t always mean the injector itself is bad. The fault could be in the wiring, connector, injector driver inside the ECU, or even a poor ground. The goal is to figure out whether you have a mechanical injector issue, an electrical circuit problem, or a control issue from the ECU.

Quick Reference

• Code: P0206
• Meaning: Injector circuit malfunction – cylinder 6
• Primary concern: Misfire, rough running, possible catalyst damage
• Severity: Moderate to high – fix as soon as possible
• Typical fix: Injector, wiring/connector repair, or ECU driver repair

Real-World Example / Field Notes

In the shop, I see P0206 most often on higher-mileage V6 and V8 engines where the rear cylinders are harder to reach and run hotter. One recent case was a pickup with a rough idle and strong fuel smell. The scan tool showed P0206 and a misfire on cylinder 6. The injector ohmed out fine on the bench, but a wiggle test on the harness made the engine stumble. The connector lock tab had broken, letting moisture in and corroding the terminals. Cleaning the pins and installing a new pigtail connector permanently fixed the issue without replacing the injector or ECU.

Symptoms of P0206

• Check engine light on: P0206 usually stores as a confirmed code and turns the MIL on.
• Rough idle: Cylinder 6 may not be fueling correctly, causing a shaky or unstable idle.
• Engine misfire: You may feel hesitation, bucking, or a “skip” under load or at cruise.
• Reduced power: Loss of one cylinder’s contribution can make the vehicle feel sluggish.
• Poor fuel economy: Misfires and incorrect fueling waste fuel and lower MPG.
• Fuel smell or rich/lean condition: Depending on failure type, you may smell raw fuel or notice black smoke.
• Hard starting: Severe injector circuit issues can cause extended cranking or no start in extreme cases.

Common Causes of P0206

Most Common Causes

• Faulty fuel injector (cylinder 6): Internal coil failure, shorted or open windings, or a stuck injector can trigger P0206.
• Damaged injector wiring harness: Chafed, pinched, or melted wires near the engine, exhaust, or valve cover are very common.
• Corroded or loose injector connector: Moisture, oil saturation, or a broken lock tab can cause intermittent contact.
• Poor ground or power supply: Shared injector power feeds or grounds that are loose or corroded can affect only one cylinder first.
• Previous engine work: After a head gasket, intake, or valve cover job, it’s easy for a harness to be pinched or not fully reconnected.

Less Common Causes

• ECU injector driver failure: The internal transistor that controls cylinder 6 can fail, especially on older or heat-stressed ECUs.
• Rodent damage: Mice and squirrels love injector harnesses; chewed wires are a frequent surprise.
• Aftermarket tuning or wiring add-ons: Poorly installed remote start, alarm, or performance modules can disturb injector circuits.
• Connector pin fit issues: Spread terminals inside the connector can look fine but lose tension and cause voltage drops.
• Water intrusion: Leaks from a cowl, hood seal, or windshield can drip onto the harness and corrode the cylinder 6 circuit first.

Diagnosis: Step-by-Step Guide

You’ll want a basic scan tool, a digital multimeter (DMM), a noid light or test light, and ideally a wiring diagram for your specific vehicle. An advanced scan tool that can view misfire counters and Mode $06 data makes the job easier, but you can still diagnose P0206 with basic tools and patience.

1. Confirm the code and check for companions. Scan for all codes. Note any related misfire codes (like P0306) or fuel trim issues. Clear the codes and see if P0206 returns quickly or only under certain conditions (hot, cold, load).
2. Inspect the harness and connector at injector 6. With the engine off, visually check the cylinder 6 injector connector and nearby wiring. Look for broken lock tabs, green corrosion, oil saturation, or rubbed-through insulation.
3. Perform a wiggle test. Start the engine and gently move the injector 6 harness and connector. If the idle changes or the engine stumbles, you likely have an intermittent wiring or connector issue.
4. Check injector resistance. Disconnect injector 6 and measure resistance across the two pins with a DMM. Compare to spec and to another known-good injector. A significantly higher, lower, or open reading points to a bad injector.
5. Verify power supply. With the key on, back-probe the injector connector. Most systems supply 12V to one side of the injector and the ECU controls the ground. Make sure you have proper battery voltage on the power feed.
6. Test ECU control (ground side). Use a noid light or test light on the control wire while cranking or running. The light should pulse. No pulse indicates an open circuit, short, or failed ECU driver.
7. Check continuity and shorts in the circuit. With the battery disconnected, use your DMM to check continuity between the injector 6 control wire and the ECU pin. Also check for shorts to power or ground. Repair any damaged sections.
8. Swap components for comparison. If access allows, swap the cylinder 6 injector with another cylinder. Clear codes and see if the fault moves. If P0206 becomes P020X for the other cylinder, the injector itself is the culprit.
9. Review live data and Mode $06. If your scan tool supports it, check misfire counters and Mode $06 data for cylinder 6. Persistent misfires with a clean electrical test may point to a mechanical issue, but P0206 is usually electrical.

Pro tip: Don’t condemn the ECU until you’ve proven power, ground, and wiring are solid. ECU injector driver failures are much less common than simple wiring or connector problems, and replacing an ECU is expensive and often requires programming.

Possible Fixes & Repair Costs

Most P0206 repairs involve restoring proper electrical control to the cylinder 6 injector. That can mean replacing the injector, repairing the harness, or in rare cases replacing the ECU. Parts quality, engine layout, and labor rates all affect the final bill.

• Replace cylinder 6 injector: $150–$400 parts and labor on many vehicles; some direct-injection or difficult-access engines can run $400–$800.
• Repair or replace injector connector/pigtail: $80–$250 depending on parts availability and how much harness needs to be spliced.
• Harness repair (chafed or melted wires): $120–$400 based on location and complexity.
• ECU repair or replacement: $500–$1,500+ including programming, usually a last resort after all other causes are ruled out.

In many real-world cases, you’re looking at a typical repair cost range of about $150–$600 when the problem is limited to a single injector or small wiring repair. Costs climb when intake manifolds must be removed for access, when multiple injectors are replaced as a set, or when ECU replacement is needed.

Can I Still Drive With P0206?

You can often drive short distances with P0206, but it’s not recommended for long-term use. A misfiring or non-firing cylinder can overheat and damage the catalytic converter, foul spark plugs, and put extra strain on the engine. In some cases the vehicle may go into a reduced-power or “limp” mode to protect itself. If the engine is shaking badly, smells strongly of fuel, or the check engine light is flashing, you should avoid driving and have it towed to a shop.

What Happens If You Ignore P0206?

Ignoring P0206 can turn a relatively simple injector or wiring repair into a much bigger job. Persistent misfires can melt the catalytic converter, wash down cylinder walls with fuel, contaminate engine oil, and damage ignition components. Over time, you may also see poor fuel economy, failed emissions tests, and more stored trouble codes, all of which increase repair costs.

Last updated: February 13, 2026

Vehicles Commonly Affected by P0206

P0206 shows up on many different makes because it’s a generic OBD-II code. In the field, it’s especially common on V6 and V8 engines where cylinder 6 is tucked near the firewall or under intake components. You’ll see it on Ford F-150 and F-250 trucks, Chevrolet and GMC Silverado/Sierra, Ram pickups, Jeep SUVs with V6 engines, Toyota and Nissan V6 sedans and crossovers, and various European models from BMW, Mercedes-Benz, and Audi. Any vehicle with individual injectors and aging wiring can set this code.