P0149 — Fuel timing error

The diagnostic definition identifies an error in fuel injection timing control. It establishes the monitored timing function, but it does not identify the failed component, the direction of the timing error or the diagnostic thresholds; those details depend on the vehicle and control strategy.

Affected system: Fuel-injection timing control

Symptoms

• Warning light may illuminate
• Related system function may be impaired
• Vehicle-specific symptoms vary

Possible causes

• Fuel supply or pressure issue, restricted injector, actuator fault, connector or wiring damage
• Related wiring, connector, power or ground fault
• Vehicle-specific mechanical or control issue

What to check

• Record stored and pending codes and freeze-frame data
• Check fuel supply and pressure readings, electrical supply and ground, and the relevant injector or regulator circuit before replacing parts.
• Confirm measured values against the vehicle service information
• Retest under the conditions that set the code
• Check fuel supply and pressure readings, electrical supply and ground, and the relevant injector or regulator circuit before replacing parts.
• Repair the verified cause and confirm the code does not return

Also written as: P0149-00, P014900, PO149 (some scan tools add the fault-type byte, e.g. -00).