O2 SensorModerate ImpactPetrol

P0135 — O2 Sensor Heater Circuit (Bank 1 Sensor 1)

Pre-catalyst O2 sensor heater malfunction detected.

5+

Affected Brands

9+

ECU Platforms

2

Related Services

7

Related DTCs

Symptoms

What the driver typically experiences when P0135 is stored

!Check Engine Light
iRich running when cold
iIncreased cold-start emissions

Why does P0135 appear after tuning?

Can appear when lambda control parameters are modified during performance tuning.

How proper calibration can address P0135

WEREMAP calibrations maintain proper sensor heater operation while optimizing fueling maps.

Related Tuning Services

Relevant services for the system behind P0135

Catalyst OffDTC Off

Related Diagnostic Codes

Codes from the same diagnostic system as P0135

P0130Moderate Impact

Diagnostic Trouble Code P0130

P0134Moderate Impact

Diagnostic Trouble Code P0134

P0132Moderate Impact

Diagnostic Trouble Code P0132

P0133Moderate Impact

Diagnostic Trouble Code P0133

P0131Moderate Impact

Diagnostic Trouble Code P0131

P0030Low Impact

HO2S Heater Control Circuit (Bank 1 Sensor 1)

P0420Moderate Impact

Catalyst System Efficiency Below Threshold (Bank 1)

Affected ECU Platforms

Marelli MM8GMKDelco E98Delco E78Delphi CRD3Siemens/Continental Sim32Siemens/Continental EMS24xxValeo V50.1Bosch MED17.2.2Bosch MED17.9.3

Commonly Affected Vehicles

Ford1.5EcoboostSiemens/Continental EMS24xx
Fiat124 SpiderMarelli MM8GMK
RenaultCaptur / QM3Valeo V50.1
FordMustangBosch MED17.2.2
HondaCivicBosch MED17.9.3
OpelAstraDelco E98

Based on data from 5+ vehicle brands. P0135 is not limited to these models.

Frequently Asked Questions

What does P0135 mean?â–¼
Pre-catalyst O2 sensor heater malfunction detected.
Why does P0135 appear after ECU tuning?â–¼
Can appear when lambda control parameters are modified during performance tuning.
How do you prevent P0135 during remapping?â–¼
WEREMAP calibrations maintain proper sensor heater operation while optimizing fueling maps.
Which vehicles are affected by P0135?â–¼
P0135 is commonly found on Ford, Fiat, Renault, Honda, Opel vehicles equipped with Marelli MM8GMK, Delco E98, Delco E78, Delphi CRD3 ECU platforms.
What other codes appear alongside P0135?â–¼
P0135 frequently appears together with P0130, P0134, P0132, P0133, P0131. These related codes typically originate from the same system modification and should be addressed together in the calibration.

Ready to Get Started?

Create your free account and access our full vehicle database and tuning services.

Create Free Account