OBD-II Monitor Testing Not Complete

What it means

This is a Ford, Lincoln and Mercury code; the same number can mean something different on other makes. It is not a fault: it means the engine computer has not yet finished all of its self-tests (readiness monitors) since codes were last cleared or the battery was disconnected. The code clears by itself once the monitors complete during normal driving.

Models covered: Ford (and Lincoln/Mercury) models with OBD-II, 1996 onwards.

Related codes: P1633P0420P0442P0455P0133

Symptoms3

• The code shows on a scan tool, usually with no check engine light.
• No change in how the car drives.
• The car may temporarily fail an emissions check because readiness is incomplete.

Possible causes5

• Codes recently cleared with a scan tool.
• Battery disconnected or replaced, or computer memory power interrupted.
• Engine computer reprogrammed or replaced.
• The car has not been driven in the conditions some monitors need, such as only short trips.
• Another fault is stopping one of the monitors from completing.

How to diagnose5

1. Read readiness monitor status with a scan tool to see which monitors are incomplete.
2. Make sure no other stored or pending fault codes exist.
3. Drive for several days including a cold start after an overnight rest, city driving and steady highway cruising.
4. Some monitors, such as EVAP, need special conditions, including a fuel level near the middle rather than full or nearly empty.
5. If the code remains after one to two weeks of varied driving, have it checked at a workshop.

How to fix5

1. Do not clear codes again, as that restarts the monitors.
2. Drive in varied conditions until the monitors complete.
3. Repair any other stored fault, since it can block monitor completion.
4. If monitors still do not complete, get a diagnosis to find which one is stuck and why.
5. Confirm with a scan tool that the code is gone and the monitors show complete.

Repair cost

In Saudi riyals; the highlighted part is the expected range for this fault.

The code usually needs no repair; the listed cost is only a diagnosis fee if it persists after enough varied driving.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions