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TuningBot DTC Database · v4.37.15

P20BD Reductant heater control B - circuit open

Generic (OBD-II) interpretation in the TuningBot DTC database.

P · PowertrainEmissionsOBD2

What P20BD means

P20BD
Reductant heater control B - circuit open Generic · emissions Data confidence 78%

The control module detected an interruption (open circuit) in the Reductant heater control B circuit, so the expected electrical continuity was not present.

Symptoms

  • MIL or SCR/AdBlue warning illuminated
  • Possible start-count-down or torque limitation on some applications

Possible causes

  • Wiring
  • reductant heater
  • ECM

Recommended checks

  • Read NOx sensor values and dosing system status
  • Check reductant level and quality data
  • Inspect dosing valve, lines and heater operation
  • Check wiring and connectors of the SCR components
  • Check for OEM technical bulletins and software updates

Related and nearby codes

How to read P20BD

P

Powertrain: engine, transmission and driveline systems.

2

Generic SAE-standard code: same meaning on every make.

0BD

Specific fault index within the subsystem.

Frequently asked questions about P20BD

What does P20BD mean?

Reductant heater control B - circuit open. The control module detected an interruption (open circuit) in the Reductant heater control B circuit, so the expected electrical continuity was not present.

Is P20BD generic or manufacturer-specific?

P20BD is a generic OBD-II code: it has the same meaning on every make and model that follows the SAE standard.

Can TuningBot remove P20BD at file level?

If the fault logic lives in the ECU calibration, yes: our DTC Removal file service disables the specific fault entry. Checksum correction is not included: it is a separate, optional service. Not sure whether your case qualifies? Request a free assessment and our engineers will check your ECU file.

Other file services

ECU tuningDyno-tested results by model and engine See the results →

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