P0208 — Injector Circuit/Open - Cylinder 8

Quick answer

• What this code means: The Powertrain Control Module (PCM) has detected an electrical fault in the fuel injector circuit for cylinder 8.
• Severity: Get towed or address immediately. Prolonged driving with this issue can cause significant engine damage, including catalytic converter failure.
• Most common cause: A failed fuel injector for cylinder 8.

What the P0208 code means

The P0208 diagnostic trouble code (DTC) officially stands for "Injector Circuit/Open - Cylinder 8." This means that the vehicle's Powertrain Control Module (PCM), which monitors and controls various engine functions, has detected an electrical fault within the circuit that operates the fuel injector for the eighth cylinder. Essentially, the PCM isn't seeing the expected electrical signal from or to the injector, indicating an open circuit (no electrical continuity) or another significant electrical issue like a short or high resistance.

In plain English, your car's computer thinks there's a problem with the electrical wiring or the injector itself for cylinder #8, preventing it from spraying fuel correctly or at all. This can lead to a misfire in that cylinder.

Common symptoms

• Check Engine Light (CEL) illuminated
• Engine misfire or rough idle
• Reduced engine power and acceleration
• Poor fuel economy
• Engine hesitation or stumbling
• Strong fuel odor from the exhaust (if the injector is stuck open or leaking)
• Engine knocking or pinging noises
• Difficulty starting the engine

Common causes

1. Faulty Fuel Injector (Cylinder 8): This is the most prevalent cause. The injector itself can fail electrically, leading to an open circuit. Internal shorts or clogs can also cause it to draw incorrect current, triggering the code.
2. Wiring Issues: Damaged, corroded, or burnt wiring in the injector circuit for cylinder 8. This could include a break in the wire, a poor connection at the injector harness, or a short to ground or power.
3. Faulty PCM (Powertrain Control Module): While less common, a defective PCM could incorrectly register an injector circuit fault. This is usually a last resort diagnosis after ruling out all other possibilities.
4. Bad Connector: A loose or corroded electrical connector at the fuel injector itself.

How a technician diagnoses it

1. Verify the Code and Freeze Frame Data: The technician will first connect an OBD-II scanner to confirm the P0208 code and check for any other related codes. They will also analyze "freeze frame data," which captures engine parameters at the moment the code was set. This provides valuable clues about operating conditions (RPM, engine load, temperature, etc.).
2. Visual Inspection: A thorough visual inspection of the cylinder 8 fuel injector and its wiring harness will be performed. They'll look for any obvious signs of damage, such as frayed wires, corrosion, or loose connections.
3. Check for Technical Service Bulletins (TSBs): The technician will check for any known TSBs related to P0208 for the specific vehicle make and model, as manufacturers sometimes identify common issues and provide repair procedures.
4. Electrical Testing of the Injector Circuit:
   • Resistance Test: The injector's resistance will be measured using a multimeter. A healthy injector typically has a resistance between 10-18 ohms (this can vary by manufacturer). A reading significantly higher (open circuit) or lower (short circuit) than specifications indicates a faulty injector. For instance, an open circuit would show "OL" (over limit) or a very high resistance reading.
   • Voltage Drop Test: With the engine running (or cranking), the technician will check for voltage at the injector connector. There should be battery voltage present on one side and a pulsed ground signal from the PCM on the other when commanded to fire. Absence of voltage or an incorrect ground signal suggests a wiring problem or a PCM issue.
   • Continuity Test: Wires leading to the injector will be tested for continuity back to the PCM connector to ensure there are no breaks in the circuit.
5. NoID Light Test: A "NoID" light (a specialized test light) can be plugged into the injector connector while cranking the engine. If the light flashes, the PCM is successfully sending a pulse to the injector, indicating the wiring and PCM are likely fine, and the injector itself is faulty. If it doesn't flash, there's a problem with the wiring or the PCM.
6. Swap Injector (for diagnosis only): In some cases, if practical, the technician might temporarily swap the cylinder 8 injector with one from another cylinder that is known to be working. If the code then follows the injector to the new cylinder, the injector is confirmed faulty. If the code remains on cylinder 8, the issue is likely wiring or PCM related.

Typical repair cost

The cost to repair a P0208 code can vary significantly based on the cause, vehicle make and model, and labor rates.

• Fuel Injector Replacement:
  • Parts: $75 - $300 per injector
  • Labor: $150 - $400 (can be higher for difficult-to-access injectors)
  • Total: $225 - $700+
• Wiring Repair:
  • Parts: Minimal (connectors, wire)
  • Labor: $100 - $350 (depending on complexity and location of the damage)
  • Total: $100 - $350
• PCM Replacement:
  • Parts: $500 - $1,500+
  • Labor: $100 - $300 (plus programming costs)
  • Total: $600 - $1,800+

Can I keep driving with this code?

No, it is highly recommended not to keep driving with a P0208 code. This code indicates a significant issue with fuel delivery to cylinder 8, which will cause a persistent misfire. Driving with a misfire can lead to:

• Catalytic Converter Damage: Unburnt fuel entering the exhaust system can overheat and permanently damage the catalytic converter, a very expensive repair.
• Engine Damage: Prolonged misfires can put excessive stress on other engine components and potentially damage pistons, valves, or spark plugs.
• Reduced Safety: The vehicle will experience reduced power and possibly erratic behavior, making it unsafe to drive, especially in traffic.

It's best to diagnose and repair this issue as soon as possible. If you must drive a short distance, proceed with extreme caution and avoid high speeds or heavy loads.

Related codes

• P0200: Injector Circuit Malfunction (Generic)
• P0201 - P0207, P0209 - P0212: Injector Circuit/Open - Cylinder 1, 2, 3, 4, 5, 6, 7, 9, 10, 11, 12 (similar issues for other cylinders)
• P0300: Random/Multiple Cylinder Misfire Detected
• P0308: Cylinder 8 Misfire Detected (often accompanies P0208)
• P0171 / P0174: System Too Lean (Bank 1 / Bank 2) - Could be related if the injector is not firing at all, leading to a lean condition.

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