P0149

What it means

P0149 is the generic code for a fuel timing error, which relates to when the fuel injection event starts. It is mainly seen on diesel engines with electronically controlled injection. The control unit has seen actual injection timing differ from the target timing, or the timing control circuit or feedback is outside its expected range.

Symptoms

• Hard starting or long cranking, especially when hot or cold
• Rough idle or misfire
• Loss of power or poor acceleration
• Excessive smoke, often white, grey or black
• Knocking or noisy combustion
• Poor fuel economy
• Engine management light on, possibly with limp mode

Possible causes

• Low fuel pressure or supply problem such as a blocked fuel filter, air in the fuel or a weak lift pumplikely
• Faulty or sticking fuel timing control valve or injection pump timing actuator (on engines that have one)likely
• Wiring or connector fault in the timing control, injection pump or related sensor circuitspossible
• Faulty crankshaft or camshaft position sensor giving poor timing referencepossible
• Injection pump or injector wear or internal fault causing actual timing to differ from commandedpossible
• Mechanical engine timing error such as a jumped or incorrectly set timing belt or chainrare
• Control unit fault or outdated calibration (only where the manufacturer has a known issue)rare

How to diagnose

1. Read all stored and pending codes and the freeze frame data, noting engine speed, load, temperature and fuel pressure when it set
2. Check for other codes, especially crank or cam sensor, fuel pressure or injector codes, and diagnose those first
3. Inspect the fuel system for leaks, air ingress, contaminated fuel and a clogged filter, and check service history
4. Inspect wiring and connectors at the injection pump, timing valve and position sensors for damage, corrosion or chafing
5. Check live data for commanded versus actual injection timing and fuel pressure, comparing with specification for the engine
6. Test crankshaft and camshaft sensor signals and the timing control valve circuit and resistance against the manufacturer's figures
7. Check the fuel supply pressure and return flow with suitable test equipment, following the procedure for that engine
8. Verify mechanical timing alignment and check for any applicable service bulletins or calibration updates for the model

How to fix

• Replace the fuel filter, bleed air from the system and repair any supply leaks or fuel lift pump faults
• Replace a faulty timing control valve or actuator, or repair the injection pump, as confirmed by testing
• Repair or replace damaged wiring and connectors in the affected circuits
• Replace a faulty crankshaft or camshaft position sensor
• Correct the mechanical engine timing if it is found to be out of position
• Apply a manufacturer calibration update only if an outdated or faulty calibration is a documented cause for that vehicle

Can I keep driving?

Nearby codes

• P0148GenericFuel Delivery Error
• P014AGenericO2 Sensor Delayed Response - Rich to Lean Bank 2 Sensor 2