P020A – Injector Circuit/Open – Cylinder 10

P020A is an OBD-II trouble code that points to a problem with one of your engine’s fuel injectors, specifically an “injector circuit/open” on a particular cylinder. When this code sets, your engine computer (ECU) is telling you it can’t properly control that injector’s electrical circuit. You might notice rough running, poor fuel economy, or a flashing check engine light. If you handle it early, repairs are usually straightforward. Ignore it too long and you risk misfires, internal engine damage, and a much higher repair bill.

What Does P020A Mean?

P020A is a generic OBD-II code that indicates the ECU has detected an electrical fault in a fuel injector circuit. In simple terms, the computer tried to command an injector on or off, and the voltage or current feedback it saw was out of the expected range, usually indicating an open or faulty circuit.

Depending on the manufacturer, P020A usually refers to a specific injector (often Injector A or a particular cylinder). The ECU monitors the injector driver and wiring. If it sees an open circuit, high resistance, or no response from that injector, it sets P020A and may also trigger misfire or fuel trim codes.

Quick Reference

• Code: P020A – Injector Circuit/Open (specific injector)
• System: Fuel injection / engine management
• Severity: Moderate to severe (can cause drivability issues)
• Common causes: Bad injector, wiring fault, connector corrosion, ECU driver fault
• Typical symptoms: Misfire, rough idle, loss of power, poor fuel economy

Real-World Example / Field Notes

In the shop, I see P020A most often on higher-mileage vehicles where the wiring harness runs close to hot engine components. One case that stands out was a mid-2010s pickup with a rough idle and strong fuel smell. Scan data showed one cylinder’s injector pulse width was commanded, but current draw was zero. A quick wiggle test on the injector connector made the engine stumble worse. Pulling the connector revealed green corrosion and a broken wire inside the insulation. After repairing the wire and cleaning the terminals, the truck ran smooth and P020A never returned.

Symptoms of P020A

• Check engine light on: Solid or flashing MIL, often with stored or pending misfire codes.
• Rough idle: Engine may shake or feel uneven, especially at stoplights or in park.
• Loss of power: Noticeable hesitation, poor acceleration, or lack of response when you press the throttle.
• Engine misfire: You may feel a stumble, bucking, or intermittent misfire under load or at cruise.
• Poor fuel economy: The ECU may overcompensate, causing higher fuel consumption.
• Hard starting: Longer crank time or needing to press the gas pedal to keep the engine running.
• Fuel smell or exhaust issues: Raw fuel smell, rough exhaust note, or even backfiring in severe cases.

Common Causes of P020A

Most Common Causes

• Faulty fuel injector: Internal open circuit, burned coil, or internal short in the injector itself.
• Damaged wiring to injector: Broken, chafed, or heat-damaged wires between the injector and ECU.
• Loose or corroded injector connector: Poor contact from moisture, corrosion, or a loose terminal.
• Harness rub-through: Wiring loom rubbed against brackets or engine components, causing an open circuit.
• Poor ground or power supply: Shared power or ground circuits for multiple injectors with high resistance.

Less Common Causes

• ECU driver failure: The internal injector driver transistor in the engine control unit can fail and stop pulsing that injector.
• Aftermarket modifications: Poorly installed remote start, performance chips, or piggyback systems spliced into injector wiring.
• Water intrusion: Moisture entering connectors or harnesses from leaks, car washes, or off-road use.
• Previous repair damage: Pinched or incorrectly routed harness after engine, head, or intake manifold work.
• Rodent damage: Mice or rats chewing through injector wires, especially on vehicles parked outside.

Diagnosis: Step-by-Step Guide

To properly diagnose P020A, you want at least a basic scan tool that can read live data, a digital multimeter, and ideally a noid light or lab scope. A wiring diagram for your specific vehicle is extremely helpful. If you’re comfortable with basic electrical testing, you can narrow down the issue before deciding on parts.

1. Confirm the code and note freeze-frame data. Use your scan tool to read P020A and any related codes (misfire, fuel trim). Note engine load, RPM, and temperature when the code set; this can help reproduce the problem.
2. Perform a visual inspection. With the engine off, inspect the affected injector and harness. Look for broken insulation, melted wires, loose connectors, or signs of rubbing against metal brackets or the valve cover.
3. Check injector connector. Unplug the injector and inspect the pins for corrosion, bent terminals, or moisture. Gently tug each wire to see if any are broken inside the insulation.
4. Test injector resistance. Using a multimeter, measure resistance across the injector terminals. Compare to factory specs. An open circuit (infinite resistance) or a reading far out of spec usually means a bad injector.
5. Verify power and ground at the connector. With the key on (engine off), check for proper voltage on the injector power feed and a good ground or ECU-controlled side, depending on the system design.
6. Use a noid light or scope. Crank or run the engine with a noid light plugged into the injector connector. A flashing light indicates the ECU is pulsing the circuit. No pulse suggests a wiring or ECU driver issue.
7. Perform a wiggle test. While monitoring the noid light or scan data (injector pulse, misfire counters), gently move the harness. If the signal cuts in and out, you’ve likely found a broken or intermittent wire.
8. Check continuity to the ECU. If power and ground look good at the injector, test continuity of the control wire(s) between the injector connector and the ECU. High resistance or an open circuit points to wiring damage.
9. Swap components if possible. On some engines, you can swap injectors between cylinders. If the problem (and code) follows the injector, the injector is faulty. If it stays on the same cylinder, suspect wiring or ECU.
10. Evaluate ECU as last resort. Only after confirming wiring and injector are good should you suspect an ECU driver failure. At that point, professional testing or ECU replacement/programming may be needed.

Pro tip: Use Mode $06 data on a more advanced scan tool to look at misfire and injector-related test results. This can show which cylinder is marginal before the code becomes permanent, helping you catch intermittent wiring issues early.

Possible Fixes & Repair Costs

Once you’ve identified the root cause, repairs for P020A are usually straightforward. Typical fixes include replacing the faulty injector, repairing or replacing damaged wiring, cleaning or replacing corroded connectors, or in rare cases, replacing the ECU. Parts and labor costs vary by vehicle, engine layout, and shop rates, but there are some common ranges.

• Fuel injector replacement: $150–$450 per injector installed, depending on access and vehicle type.
• Injector connector repair: $80–$250, including pigtail replacement and solder/heat-shrink work.
• Harness repair or replacement: $150–$600, more if the main engine harness must be replaced.
• ECU replacement/programming: $500–$1,500+, depending on OEM vs reman and required coding.

Factors that affect cost include how difficult the injector is to reach, whether the intake manifold must be removed, local labor rates, and whether additional parts (seals, rail gaskets, clips) are replaced at the same time.

Can I Still Drive With P020A?

You can sometimes drive short distances with P020A, but it’s not recommended for long or repeated trips. If the injector circuit is open, that cylinder may not be getting fuel, causing a constant misfire. Driving like this can overheat the catalytic converter, wash down cylinder walls if fuel delivery is erratic, and leave you stranded if the problem worsens. If the check engine light is flashing or the engine runs very rough, you should avoid driving and have the vehicle towed to prevent further damage.

What Happens If You Ignore P020A?

Ignoring P020A can turn a relatively simple electrical or injector repair into major engine work. A persistent misfire can damage the catalytic converter, foul spark plugs, and cause excessive wear on pistons and rings. Over time, you may see reduced performance, poor fuel economy, and potential internal engine damage that costs far more than fixing the injector circuit early.

Last updated: January 22, 2026

Vehicles Commonly Affected by P020A

P020A can show up on almost any OBD-II vehicle, but it’s more frequently seen on higher-mileage models and engines where injector wiring runs close to hot components. In the field, this code is common on domestic trucks and SUVs from Ford, GM (Chevrolet, GMC), and Ram, especially V6 and V8 engines. It also appears on many Japanese and Korean vehicles such as Toyota, Honda, Nissan, Hyundai, and Kia with multi-port fuel injection. Turbocharged engines and direct-injection setups in European brands like Volkswagen, Audi, BMW, and Mercedes-Benz can also trigger P020A when wiring or injectors start to age.