P1303
EGR Calibration Fault.
- Ford
- Powertrain
- Manufacturer code
- Medium severity
How this code is built
- P
- SystemPowertrain
- 1
- Defined byThe manufacturer
- 3
- AreaIgnition system or misfire
- 03
- FaultThe specific fault in that area
What it means
P1303 on a Ford means the engine control unit has found a fault in the exhaust gas recirculation (EGR) system calibration. The EGR flow or valve position it measured did not match what it commanded during its self-check. The exact strategy and sensor used differ by model and engine, so confirm the details for the vehicle in front of you.
Symptoms
- Engine warning light on
- Rough or unstable idle
- Hesitation or poor throttle response under load
- Slight pinking or knocking on acceleration
- Occasional stalling or surging at light throttle
- Failed emissions test
Possible causes
- EGR valve sticking or clogged with carbon depositslikely
- Blocked EGR passages or pipeworklikely
- Faulty EGR position or pressure feedback sensorpossible
- Vacuum leak or split vacuum hose to the EGR valve or its control solenoidpossible
- Damaged wiring or poor connector contact in the EGR circuitpossible
- Faulty EGR control solenoid or valve actuatorpossible
- Fault within the engine control unit or outdated calibrationrare
How to diagnose
- Read all stored and pending codes and note the freeze frame data, then check for related EGR, MAP or air flow codes.
- Check for technical service bulletins or software updates for the specific model and engine.
- Visually inspect the EGR valve, vacuum hoses, pipework and wiring for cracks, splits, leaks, heat damage or loose connectors.
- Check the connectors for corrosion, bent pins and a secure fit, and test the wiring for continuity and shorts.
- Test the vacuum supply and the control solenoid operation, and check that the valve holds vacuum if it is vacuum operated.
- With a scan tool, command the EGR valve and watch the position or pressure feedback and the effect on idle.
- Remove the EGR valve and inspect it and the passages for carbon build-up and a valve that does not seat or move freely.
- Measure the feedback sensor signal against the specification for the model.
How to fix
- Clean or replace the EGR valve if it is sticking or heavily carboned.
- Clear the blocked EGR passages and pipework of deposits, or replace damaged pipes.
- Replace the faulty EGR position or pressure sensor.
- Replace split or perished vacuum hoses and repair leaks, and replace a faulty control solenoid.
- Repair damaged wiring or connectors in the EGR circuit.
- Apply a software update to the control unit only if an outdated calibration is confirmed as the cause for that model.
Can I keep driving?
Medium severity
The car can usually be driven for a short time, but book it in soon as drivability may worsen and a stuck EGR valve can raise combustion temperatures and emissions. Avoid heavy loads, and stop if the engine runs very roughly or stalls.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.