Emissions / AuxiliaryLow ImpactDiesel

P0402 — Diagnostic Trouble Code P0402

OBD-II diagnostic code P0402 relates to the emissions / auxiliary system. This code is logged when the ECU detects a parameter outside its expected operating range.

4+

Affected Brands

9+

ECU Platforms

2

Related Services

6

Related DTCs

Symptoms

What the driver typically experiences when P0402 is stored

!Check Engine Light
iFailed emissions test
iNo major drivability impact

Why does P0402 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 P0402

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 P0402

EGR OffDTC Off

Related Diagnostic Codes

Codes from the same diagnostic system as P0402

P0401Low Impact

Exhaust Gas Recirculation (EGR) Flow Insufficient

P0403Low Impact

Exhaust Gas Recirculation (EGR) Control Circuit

P0101Moderate Impact

Mass Air Flow (MAF) Sensor Range/Performance

P0400Low Impact

Exhaust Gas Recirculation Flow

P0409Low Impact

Diagnostic Trouble Code P0409

P0404Low Impact

Diagnostic Trouble Code P0404

Affected ECU Platforms

Bosch EDC17CP46Bosch EDC16C34Bosch EDC17C69Bosch EDC17CP57Bosch EDC17CP44Bosch EDC17-CP14Bosch EDC16C39Siemens/Continental SID20XSiemens SID20x

Commonly Affected Vehicles

SuzukiVitaraBosch EDC17C69
PorscheCayenneBosch EDC17CP44
MBGLKBosch EDC17CP46
MBGLBosch EDC17CP46
Peugeot308Bosch EDC16C34

Based on data from 4+ vehicle brands. P0402 is not limited to these models.

Frequently Asked Questions

What does P0402 mean?â–¼
OBD-II diagnostic code P0402 relates to the emissions / auxiliary system. This code is logged when the ECU detects a parameter outside its expected operating range.
Why does P0402 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 P0402 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 P0402?â–¼
P0402 is commonly found on Suzuki, Porsche, MB, Peugeot vehicles equipped with Bosch EDC17CP46, Bosch EDC16C34, Bosch EDC17C69, Bosch EDC17CP57 ECU platforms.
What other codes appear alongside P0402?â–¼
P0402 frequently appears together with P0401, P0403, P0101, P0400, P0409. These related codes typically originate from the same system modification and should be addressed together in the calibration.

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