P026B: Injection Timing Performance

What it means

Generic injection timing performance fault — actual timing deviates from target.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test
• The engine or gearbox may go into limp mode

How it works

The engine control module calculates when fuel injection should occur and compares the target timing with feedback from timing sensors and control components. This code sets when actual injection timing does not track the target closely enough, which can affect starting, combustion, and engine power.

Common causes

Most likely first.

1. Injector timing control or actuator fault
2. Faulty timing sensor or signal
3. Wiring or connector fault
4. Fuel pressure or delivery problem

Symptoms

• Check-engine light
• Rough running or misfire
• Hard starting
• Reduced power

How to diagnose it

1. Review freeze-frame data and live commanded-versus-actual injection timing, if available, to see when the deviation occurs.
2. Inspect the timing sensor connectors and wiring for damage, loose connections, or contamination that could corrupt the timing signal.
3. Check fuel level and relevant fuel pressure or delivery data against the manufacturer's specification, since inadequate supply can interfere with timing control.
4. Test the timing sensor signals and injector timing actuator or control circuit using the vehicle wiring diagram and specified procedure.
5. If sensor, wiring, and fuel supply checks pass, investigate the mechanical timing system according to the manufacturer's procedure.

Common fixes

• Repair loose, damaged, or contaminated timing sensor connections.
• Repair wiring faults in the timing sensor or injector timing control circuit.
• Restore fuel supply by correcting a confirmed restriction or pressure problem.
• Replace a faulty timing sensor or actuator after testing identifies it.
• Correct mechanical timing if tests show it is out of specification.

Can I keep driving?

Because this fault may trigger reduced-power operation, avoid high speeds, heavy loads, and long trips; arrange diagnosis promptly. Stop if the engine runs very roughly, is difficult to control, or loses substantial power.