Emissions / AuxiliaryLow ImpactDiesel & Petrol

P0408 — Diagnostic Trouble Code P0408

OBD-II diagnostic code P0408 relates to the emissions / auxiliary system. This code is logged when the ECU detects a parameter outside its expected operating range.

3+

Affected Brands

4+

ECU Platforms

2

Related Services

3

Related DTCs

Symptoms

What the driver typically experiences when P0408 is stored

!Check Engine Light
iFailed emissions test
iNo major drivability impact

Why does P0408 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 P0408

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 P0408

EGR OffDTC Off

Related Diagnostic Codes

Codes from the same diagnostic system as P0408

P0406Low Impact

Diagnostic Trouble Code P0406

P0405Low Impact

EGR Position Sensor Circuit Low

P0403Low Impact

Exhaust Gas Recirculation (EGR) Control Circuit

Affected ECU Platforms

Bosch MED17.7.3.1Siemens/Continental PRC2.1PCR2.1 unknownSiemens/Continental SID20X

Commonly Affected Vehicles

MBE / E CoupeBosch MED17.7.3.1
VWGolfSiemens/Continental PRC2.1
VWPoloPCR2.1 unknown
Jaguar2.7DSiemens/Continental SID20X

Based on data from 3+ vehicle brands. P0408 is not limited to these models.

Frequently Asked Questions

What does P0408 mean?â–¼
OBD-II diagnostic code P0408 relates to the emissions / auxiliary system. This code is logged when the ECU detects a parameter outside its expected operating range.
Why does P0408 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 P0408 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 P0408?â–¼
P0408 is commonly found on MB, VW, Jaguar vehicles equipped with Bosch MED17.7.3.1, Siemens/Continental PRC2.1, PCR2.1 unknown, Siemens/Continental SID20X ECU platforms.
What other codes appear alongside P0408?â–¼
P0408 frequently appears together with P0406, P0405, P0403. These related codes typically originate from the same system modification and should be addressed together in the calibration.

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