P0042
HO2S Heater Control Circuit (Bank 1 Sensor 3)
System: Emissions
Severity: medium
What does P0042 mean?
The DTC P0042 (HO2S Heater Control Circuit (Bank 1 Sensor 3)) is a fault code stored by the ECU when it detects a heater B1S3 condition in the emissions subsystem. It is commonly seen on European and Asian vehicles using Bosch, Continental, Siemens or Denso ECUs.
Common causes of P0042
- Failed sensor heater
- Wiring fault
- Often diesel post-DPF NOx sensor
How to fix P0042
Diesels: usually NOx or post-DPF sensor. Often paired with SCR/AdBlue codes.
Tuning approach with DaVinci Deluxe
For P0042, DaVinci Deluxe offers the following ECU map adjustments and software solutions:
- Post-DPF sensor disable (where legal)
- NOx monitor disable
Need to fix P0042 on your ECU?
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