P2673: Injection Pump Timing Calibration Not Learned

What it means

The injection pump timing learning routine did not complete successfully. Without learned values, injection timing runs from default tables and combustion is suboptimal.

At a glance

• Usually lights the check-engine light

How it works

The engine control module learns how the injection pump's timing actuator affects injection timing, then uses those learned values to refine its default calibration. P2673 sets when the timing calibration routine cannot complete, so the module continues using default timing tables.

Common causes

Most likely first.

1. Learning routine aborted by other DTC or unstable conditions
2. Timing actuator drift outside learning window

Symptoms

• Check-engine light
• Hard starting
• Rough or uneven running

How to diagnose it

1. Read freeze-frame data and check for other active engine or fuel-system codes that may have interrupted the pump timing learning routine.
2. Confirm the battery is charged and the engine meets the manufacturer's conditions for running the timing calibration, since unstable conditions can abort learning.
3. Inspect the injection pump timing actuator, its connector, and nearby wiring for damage, loose connections, or contamination.
4. Use a scan tool to run the pump timing learning routine and observe whether it starts, completes, or reports a value outside its learning window.
5. If learning still fails, test the timing actuator and its circuit against the manufacturer's specification and check for mechanical timing or actuator travel problems.

Common fixes

• Resolve other active faults or unstable operating conditions that prevent the learning routine from running.
• Repair a loose, damaged, or contaminated timing actuator connector or wire.
• Replace a failed injection pump timing actuator if its circuit and operation do not meet the manufacturer's specification.
• Correct injection pump timing or mechanical travel issues, then run the calibration routine again.

Can I keep driving?

If the engine starts and runs smoothly, a short, gentle trip may be possible, but hard starting or rough running can worsen and performance may be poor. Avoid long trips or heavy loads until the timing calibration issue is corrected.