OBD-II Code P0289 — What It Means & How to Fix It

What Does This Error Mean?

P0289 means the fuel injector circuit for Cylinder 10 is reading a high voltage or current signal. The ECM controls injectors by switching their ground circuit and monitoring the electrical response. When the Cylinder 10 circuit reads higher than expected, it points to a short to voltage or an internally shorted injector. This code only appears on V10 and V12 engines. A stuck-open injector scenario causes over-fueling on Cylinder 10, leading to a strong fuel smell, rough running, and potential catalytic converter damage.

Affected Models

All vehicles 1996+ with 10 or more cylinders
Common in Ford 6.8L V10 Triton (F-250/F-350/Excursion)
Common in Dodge Viper V10
Common in V12 luxury vehicles

Common Causes

Short to voltage in the Cylinder 10 injector control wiring
Internally shorted Cylinder 10 injector drawing excessive current
Wiring harness damage where the Cylinder 10 control wire contacts a 12V source
Wrong-specification injector installed with a lower resistance rating than required
ECM driver failure for Cylinder 10 stuck in a high output state

How to Fix It

Inspect the Cylinder 10 injector wiring harness for any bare, melted, or misrouted wires contacting power sources. On V10 trucks the rear injector harness is long and can contact battery cables, the firewall power junction, or alternator wiring in the engine bay.

Take a photo of the harness routing before disturbing it — this helps confirm correct reinstallation after any repairs.
With the Cylinder 10 injector unplugged and key ON, measure voltage on the control wire terminal in the harness connector. It should read near zero when the ECM is not commanding it. A 12V reading confirms a short to power in the control wire.

Wiggle the harness in different directions while watching the meter — intermittent shorts appear during movement at the location of the fault.
Test the Cylinder 10 injector resistance by probing its terminals directly. A near-zero reading (well below the normal 10–18 ohm spec) indicates an internal short. The injector is drawing excess current and staying open too long — it must be replaced.

Operating with a near-zero resistance injector risks damaging the ECM driver circuit from overcurrent.
Verify injector part number and specifications if injectors were recently replaced. V10 engines have had various injector upgrades over model years — installing a low-impedance injector in a circuit calibrated for high-impedance injectors will always trigger a high-circuit code.

Confirm the OEM part number for your specific engine code and model year before purchasing replacement injectors.
If all physical components test normal, have a shop verify the ECM's Cylinder 10 driver output with a lab scope. Confirm the ECM is genuinely at fault before purchasing a replacement. ECM failures are real but much less common than wiring or injector problems.

Ask about OEM remanufactured ECMs — they're typically much cheaper than new and come with a warranty.

When to Call a Professional

A high-circuit fault causing the Cylinder 10 injector to stay open is a serious issue on any engine — and especially so on large V10 or V12 engines. Over-fueling damages oxygen sensors and catalytic converters rapidly. The cost of converters on V10 trucks and exotic V12 vehicles can be extremely high. Seek professional diagnosis quickly if you detect fuel smell or black smoke from the exhaust.

Frequently Asked Questions

Is P0289 rare?

It's uncommon compared to codes like P0300 or P0420 simply because V10 and V12 engines are less common than V6 or V8 engines. Among V10 truck owners — particularly Ford 6.8L Triton owners — injector circuit codes including P0289 are occasionally reported, especially on vehicles with 150,000+ miles.

Can driving with P0289 void my warranty?

If the vehicle is still under warranty, you should report this code to the dealer as soon as it appears. Delaying repair of a fault that causes engine or catalytic converter damage could potentially complicate a warranty claim. Document when the code first appeared and when you reported it.

How much does it cost to fix P0289?

Wiring repair: $150–$400. Injector replacement: $200–$600 installed. ECM repair or replacement: $400–$1,500+. Catalytic converter if damaged: $800–$2,500+ per unit on large V10 vehicles.