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AutoCodes – Generic – P20B1

P20B1 Code - Diesel Exhaust Fluid Reductant Heater Control Valve Circuit Open

Quick Answer

The Diesel Exhaust Fluid (DEF) Tank Level Sensor and Diesel Exhaust Fluid (DEF) Tank Temperature Sensor are a combination sensor used to measure the level and temperature of the fluid in the DEF Tank. Common causes include Faulty Diesel Exhaust Fluid Reductant Heater Control Valve, Diesel Exhaust Fluid Reductant Heater Control Valve harness is open or shorted, Diesel Exhaust Fluid Reductant Heater Control Valve circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means
P20B1 indicates Diesel Exhaust Fluid Reductant Heater Control Valve Circuit Open.
Common causes
Common causes include Faulty Diesel Exhaust Fluid Reductant Heater Control Valve, Diesel Exhaust Fluid Reductant Heater Control Valve harness is open or shorted, Diesel Exhaust Fluid Reductant Heater Control Valve circuit poor electrical connection.
Severity
High - diagnose this code as soon as possible.
Can I drive?
Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
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Code Popularity 29,267
How popular is this code, among other codes? Low
What is this?
Table of contents Created and updated by William Orellana on Jul 15, 2024
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Code P20B1 Description

The Diesel Exhaust Fluid (DEF) Tank Level Sensor and Diesel Exhaust Fluid (DEF) Tank Temperature Sensor are a combination sensor used to measure the level and temperature of the fluid in the DEF Tank. Though combined, the level sensor and the temperature sensor operate independently of each other. Both sensors operate as a two-wire 5-Volt sensor. The DEF Tank Level Sensor is a 14-point magnetic reed switch sensor. The DEF Tank Temperature Sensor is a negative temperature coefficient sensor. The DEF Dosing Control Unit will illuminate the MIL lamp via the Powertrain Control Module (PCM) immediately after this diagnostic runs and fails. The DEF Dosing Control Unit will turn off the MIL lamp via the PCM immediately after the diagnostic runs and passes in three consecutive key cycles. This monitor runs a short time after Diesel Exhaust Fluid Tank heating is commanded. The Diagnostic Trouble Code (DTC) will be set when the DEF Dosing Control Unit detects a Diesel Exhaust Fluid Reductant Heater Control Valve circuit open.
OBDII Code P20B1 - Diesel Exhaust Fluid Reductant Heater Control Valve Circuit Open - AutoCodes.com
P20B1 Code - Diesel Exhaust Fluid Reductant Heater Control Valve Circuit Open
What does this mean?

What are the Possible Causes of the DTC P20B1?

  • Faulty Diesel Exhaust Fluid Reductant Heater Control Valve
  • Diesel Exhaust Fluid Reductant Heater Control Valve harness is open or shorted
  • Diesel Exhaust Fluid Reductant Heater Control Valve circuit poor electrical connection

How to Fix the DTC P20B1?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P20B1 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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Information for Specific Makes

  • P20B1 Dodge — Diesel Exhaust Fluid Reductant Heater Control Valve Circuit Open
  • P20B1 RAM — Diesel Exhaust Fluid Reductant Heater Control Valve Circuit Open
About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P20B1 Code

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