Faulty ignition coil or spark plug on cylinder 10; Faulty or clogged fuel injector on cylinder 10, or a fault in its wiring or connector; Vacuum or intake air leak affecting cylinder 10; Low compression on cylinder 10 (worn rings, burnt valve, head gasket leak); Wiring or connector damage to the injector or coil circuit, including a poor earth or supply; Fuel supply problem such as low fuel pressure or contaminated fuel; Fault in the engine control unit driver circuit.

P0290

Cylinder 10 Contribution/Balance.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
2: AreaFuel and air metering (injector circuit)
90: FaultThe specific fault in that area

What it means

P0290 is the generic code for a fault in the cylinder 10 contribution or balance circuit. The engine control unit monitors how much each cylinder contributes to engine speed, and it has seen cylinder 10 contributing noticeably less (or more) than the others. It only applies to engines with ten or more cylinders, and the exact monitoring method varies by engine.

Symptoms

Rough idle or noticeable engine shake
Misfire or hesitation under load
Loss of power and poor acceleration
Raised fuel consumption
Malfunction indicator lamp on, possibly flashing under load
Fuel smell or hard starting in some cases

Possible causes

Faulty ignition coil or spark plug on cylinder 10likely
Faulty or clogged fuel injector on cylinder 10, or a fault in its wiring or connectorlikely
Vacuum or intake air leak affecting cylinder 10possible
Low compression on cylinder 10 (worn rings, burnt valve, head gasket leak)possible
Wiring or connector damage to the injector or coil circuit, including a poor earth or supplypossible
Fuel supply problem such as low fuel pressure or contaminated fuelrare
Fault in the engine control unit driver circuitrare

How to diagnose

Read all stored and pending codes and the freeze frame data, noting engine load, speed and temperature when the fault set. Check for related misfire codes, especially for cylinder 10.
Confirm which physical cylinder is number 10 and which bank it is on, as numbering depends on the engine. Check the workshop data for that model.
Inspect the coil, injector and wiring connectors for cylinder 10 for damage, corrosion, oil contamination or poor fit.
Check live data for misfire counts and fuel trims on the relevant bank, and look for lean or rich trends.
Swap the coil (and plug if appropriate) from cylinder 10 with a neighbouring cylinder and see whether the fault follows.
Test the injector's resistance and operation, and check its drive signal at the connector.
Check for intake leaks, using a smoke test if needed, and check fuel pressure against the manufacturer's specification.
If the fault persists, carry out a compression or cylinder leak-down test on cylinder 10.

How to fix

Replace the faulty ignition coil and/or spark plugs on cylinder 10, and consider replacing the plugs as a set.
Clean or replace the cylinder 10 injector as testing indicates.
Repair or replace damaged wiring or connectors in the coil or injector circuit.
Repair intake or vacuum leaks by replacing the faulty hose, gasket or seal.
Carry out the necessary mechanical repair if compression is low, such as valve or piston ring work or a head gasket repair.

Can I keep driving?

Medium severity

The car can be driven gently for a short time to get it to a workshop, but avoid heavy loads. If the warning lamp flashes, reduce load or stop, because unburnt fuel can damage the catalytic converter.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.