OBD-II Code P0294 — What It Means & How to Fix It

What Does This Error Mean?

P0294 means the fuel injector circuit for cylinder 10 is reading too low a voltage. The ECM can't send a proper signal to fire the injector, meaning cylinder 10 may be running without fuel. This is the low-voltage counterpart to P0293. Expect rough idle, vibration, and reduced power on a V10 or V12 engine. This code needs prompt attention to prevent catalytic converter damage.

Affected Models

All vehicles 1996+ with 10+ cylinders
Common in Ford Excursion V10
Common in Dodge Viper V10
Common in BMW V12 models
Common in large diesel trucks

Common Causes

Open or broken wire in the injector circuit — a wire that has lost continuity
Fuel injector with a failed internal coil that reads open on a multimeter
Corroded or disconnected injector connector creating a circuit break
Blown injector fuse or faulty relay cutting power to the cylinder 10 injector
ECM driver output failure — the ECM can no longer drive the injector circuit

How to Fix It

Start with an OBD-II scanner to pull all codes. If you also see P0310 (cylinder 10 misfire), it confirms the injector is not firing. This combination tells you cylinder 10 is definitely not contributing to engine power.

Note the freeze frame data — it shows engine conditions when the code was first triggered.
Check the fuse box for any blown fuses in the injector circuit. Refer to your owner's manual fuse diagram. A blown fuse is the easiest and cheapest fix — always rule this out first.

Some vehicles use a separate fuse for each injector bank. Check both the main fuse box and any underhood junction box.
Find and unplug the cylinder 10 injector connector. Inspect both sides — the connector on the wiring harness and the connector on the injector. Look for pushed-back pins, corrosion, or melted plastic. Clean and reconnect firmly.

Even a small amount of oxidation on the pins can create enough resistance to trigger a low voltage code.
Test the injector coil with a multimeter. Unplug the injector and measure resistance across its two terminals. A reading of OL (open loop / infinite resistance) means the injector coil is burned out and the injector must be replaced.

Normal injector resistance is 10-17 ohms for high-impedance injectors.
If the injector tests good, use a multimeter in continuity mode to test the wiring from the injector connector back toward the ECM. An open circuit somewhere in that wire is your culprit. Repair or replace the damaged wire segment.

Rodent damage and heat damage near the exhaust are the two most common causes of open injector wires.

When to Call a Professional

If fuses and connectors check out, tracing an open wire on a large engine harness is best left to a mechanic with a wiring diagram. Confirm the injector is the cause before spending on ECM repair. A good mechanic can isolate the open circuit in less than an hour. Diagnosis is typically $100-$200, injector replacement $150-$400 installed.

Frequently Asked Questions

What is the difference between P0293 and P0294?

P0293 is a HIGH voltage condition — the circuit has too much voltage, usually from a short. P0294 is a LOW voltage condition — the circuit voltage is too low, usually from an open or broken wire. Both affect the cylinder 10 injector. P0294 is more commonly caused by a dead injector coil or broken wire.

Can I temporarily drive with P0294?

Short trips are possible, but it's not advisable for long drives. With cylinder 10 not firing, the engine is running on fewer cylinders than designed. This creates vibration, reduced power, and increased exhaust emissions. Unburned fuel entering the catalytic converter can cause costly damage within days.

How do I know if the injector is bad versus the wiring?

Disconnect the injector and test its resistance with a multimeter. If the injector reads correctly (10-17 ohms), the injector coil is fine — the problem is in the wiring. If the injector reads open (OL) or shorted (0 ohms), replace the injector. This simple test saves you from guessing and buying the wrong part.