Ignition / MisfireHigh ImpactPetrol

P0303 — Diagnostic Trouble Code P0303

OBD-II diagnostic code P0303 relates to the ignition / misfire system. This code is logged when the ECU detects a parameter outside its expected operating range.

6+

Affected Brands

11+

ECU Platforms

3

Related Services

8

Related DTCs

Symptoms

What the driver typically experiences when P0303 is stored

!Check Engine Light (may flash)
iEngine misfires
iRough idle
iLoss of power

Why does P0303 appear after tuning?

This code may appear after ECU modifications when the affected system monitoring has not been fully recalibrated for the new operating parameters.

How proper calibration can address P0303

WEREMAP professional calibrations include comprehensive diagnostic management for all affected systems, preventing unnecessary fault codes while maintaining safe operation.

Related Tuning Services

Relevant services for the system behind P0303

Stage 1Stage 2DTC Off

Related Diagnostic Codes

Codes from the same diagnostic system as P0303

P0300High Impact

Random/Multiple Cylinder Misfire Detected

P0302High Impact

Diagnostic Trouble Code P0302

P0301High Impact

Diagnostic Trouble Code P0301

P0304High Impact

Diagnostic Trouble Code P0304

P0306High Impact

Diagnostic Trouble Code P0306

P0017Moderate Impact

Diagnostic Trouble Code P0017

P0014Moderate Impact

Diagnostic Trouble Code P0014

P0366High Impact

Diagnostic Trouble Code P0366

Affected ECU Platforms

Bosch MED17.7.2Bosch MG1CS015Bosch MED17.1.9Bosch MED17.1.9 MED17.9.9Bosch MED 17.7.7Bosch MED17.4.2Bosch MED17Bosch MED9.6Mitsubishi L3EC-188K2-ASiemens/Continental SIMOS10.2xSiemens/Continental SIMOS10.1x

Commonly Affected Vehicles

FordF150Bosch MG1CS015
Land RoverRange RoverBosch MED17.1.9
MBGLC / GLC Coup�Bosch MED 17.7.7
Peugeot308Bosch MED17.4.2
MBA / A BerlineBosch MED17.7.2
Land RoverRange Rover EvoqueBosch MED17
FerrariFFBosch MED9.6
MazdaMazda 3Mitsubishi L3EC-188K2-A

Based on data from 6+ vehicle brands. P0303 is not limited to these models.

Frequently Asked Questions

What does P0303 mean?â–¼
OBD-II diagnostic code P0303 relates to the ignition / misfire system. This code is logged when the ECU detects a parameter outside its expected operating range.
Why does P0303 appear after ECU tuning?â–¼
This code may appear after ECU modifications when the affected system monitoring has not been fully recalibrated for the new operating parameters.
How do you prevent P0303 during remapping?â–¼
WEREMAP professional calibrations include comprehensive diagnostic management for all affected systems, preventing unnecessary fault codes while maintaining safe operation.
Which vehicles are affected by P0303?â–¼
P0303 is commonly found on Ford, Land Rover, MB, Peugeot, Ferrari, Mazda vehicles equipped with Bosch MED17.7.2, Bosch MG1CS015, Bosch MED17.1.9, Bosch MED17.1.9 MED17.9.9 ECU platforms.
What other codes appear alongside P0303?â–¼
P0303 frequently appears together with P0300, P0302, P0301, P0304, P0306. These related codes typically originate from the same system modification and should be addressed together in the calibration.

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