P0208
PowertrainCylinder 8 Injector Circuit Malfunction
This can go either way on cost, so don't panic before you've tested it. The cheap end is a corroded connector or chafed wire to the number 8 injector, the dear end is a failed injector or an injector driver inside the ECU. The code points at the electrical side of the circuit feeding cylinder 8's injector, not a blocked nozzle, so you're chasing wiring and voltage rather than fuel flow. On most cars this only turns up on V8 or straight-eight engines, since cylinder 8 simply doesn't exist on a four-pot.
ⓘ Information only. This page provides general educational information about fault code P0208. We do not assess the urgency or safety implications of any specific fault. That requires in-person diagnosis by a qualified mechanic. Full terms.
Recommended next steps
Whether a fault is urgent, drivable, or routine depends entirely on the cause on a specific vehicle, and that can only be determined by a qualified mechanic with diagnostic equipment. If a warning light is illuminated, the most reliable next step is professional diagnosis.
What does P0208 mean?
P0208 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Cylinder 8 Injector Circuit Malfunction.
This is a standardised OBD-II code. The technical definition is the same regardless of the make or model of vehicle, although specific causes and symptoms can vary between vehicles.
Symptoms commonly associated with this code
Symptoms that drivers often report alongside this code. Not all may apply to every case:
- • Engine warning light on, sometimes with a flashing light if cylinder 8 is properly dead
- • Lumpy idle, worst from cold and you can often feel it through the gearstick or seat
- • Down on power and a flat spot when you put your foot down
- • A regular stumble or misfire that you can hear at idle as one cylinder dropping out
- • Heavier on fuel and a sharp smell from the exhaust if it's been misfiring for a while
- • Car drops into limp mode and won't rev past a set point to save the engine
Possible causes
Causes commonly associated with P0208, listed in approximate order of typical investigation. The actual cause on a specific vehicle can only be confirmed by professional diagnosis.
- 1. Corroded or loose connector at the injector, top of the list because the pins sit in a warm, vibrating engine bay and pick up moisture
- 2. Chafed or broken wire in the harness run to cylinder 8, often where the loom rubs against a bracket or the head
- 3. Failed injector itself, the coil inside goes open or shorts and the ECU reads it as a circuit fault
- 4. Short to earth or an open circuit somewhere in the injector wiring, sometimes caused by a previous botched repair
- 5. Water or oil getting into the connector and pushing the resistance up and down, which gives you an intermittent code that comes and goes
- 6. Failed injector driver transistor inside the ECU, less common and the last thing you should suspect rather than the first
How mechanics typically diagnose
A typical diagnostic sequence used by mechanics, provided here for educational reference only. Diagnostic work should be performed by a qualified mechanic with the appropriate tools and training.
- 1. Read all the stored codes first and note whether you've got a P0308 misfire alongside it. The two together usually mean cylinder 8 really is dropping out, not just a phantom electrical glitch.
- 2. Unplug the cylinder 8 injector connector and have a proper look. Bent pins, green corrosion, oil in the plug, a melted shell. This is where a lot of these jobs end.
- 3. Measure the injector coil resistance with the plug off and the meter on the injector pins. Most petrol injectors read somewhere around 12 to 16 ohms, diesel solenoid types are lower. Way off spec or open circuit and the injector is your fault.
- 4. Check you've got supply voltage at the connector with the ignition on, and that the earth/control side is switching during cranking. No supply points back up the harness toward the ECU.
- 5. Wiggle-test the harness with the meter connected if the fault is intermittent, flexing the loom near brackets and the head to catch a break that only shows up under vibration.
- 6. If the wiring, connector and injector all check out, you're left looking at the ECU driver. Confirm that on a known-good circuit before condemning an expensive control module.
Common questions about P0208
How long can I keep driving like this before something gets wrecked? +
Short trips to get it home or to a garage are fine, but don't run it like this for weeks. A misfiring cylinder 8 dumps raw fuel into the exhaust, and that cooks the catalytic converter, which is a far bigger bill than the injector. If the engine warning light is flashing, that means an active misfire and you should stop driving and sort it before the cat dies. Steady amber light with mild roughness gives you a bit more breathing room, but treat it as a job to book in this week, not next month.
Is it the injector that's gone, or just the wiring and plug feeding it? +
P0208 is an electrical circuit code, so it's flagging the whole loop and not the spray pattern of the injector. Plenty of these turn out to be a corroded connector or a rubbed-through wire rather than a dead injector, which is why you test before you buy parts. Resistance check the injector coil and check for supply and earth at the plug. If the injector reads in spec and the wiring is sound, then you can point the finger at the injector or, last of all, the ECU driver. Fitting an injector on a hunch is a good way to spend money and still have the light on.
How long is it in the garage for? +
Diagnosis alone is usually an hour or so once they're hooked up and probing the circuit. A connector clean or a wiring repair is often done the same morning. Replacing the injector is the variable bit. On a V8 with the inlet manifold over the top of the rear cylinders, getting at number 8 can swallow a few hours of labour on its own. ECU driver problems mean either repairing or reprogramming a control module, and that can stretch to a day depending on parts availability and coding.
Information only, not professional advice
The information on this page is provided for general guidance and educational purposes only. It is not a substitute for diagnosis or repair advice from a qualified mechanic. Always verify any fault before paying for repairs. carfaultcodes.co.uk accepts no liability for decisions made based on this information. Full terms →