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P20B9 GMC Code - Reductant Heater 1 Control Circuit

- Code Popularity: 8,126 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
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What are the Possible Causes of the DTC P20B9 GMC?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Faulty Reductant Heater
  • Reductant Heater harness is open or shorted
  • Reductant Heater circuit poor electrical connection
  • Faulty Reductant Pump and Sensor Assembly
  • Faulty Reductant Control Module
⚠ Does your GMC have Safety Recalls? → Check here

How to Fix the DTC P20B9 GMC?

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

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What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P20B9 GMC code, it typically requires 1.0 hour of labor. The specific diagnosis time and labor rates at auto repair shops can differ based on factors such as the location, make and model of the vehicle, and even the engine type. It is common for most auto repair shops to charge between $75 and $150 per hour.

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)

Code P20B9 GMC Description

As reductant will freeze at temperatures below -11°C (12°F), there are 2 reductant heaters located in the reductant tank. One heats the reductant in the tank, and one heats the reductant supplied to the reductant injector supply pipe. The Engine Control Module (ECM) monitors the reductant temperature in the tank in order to determine if the reductant temperature is below its freeze point. If the ECM determines that the reductant may be frozen, it activates a "defrost strategy" energizing the reductant eater. This energizing action terminates when the temperature sensor measures a threshold value over which the heater must be deactivated.
The Diagnostic Trouble Code (DTC) will be set when the ECM indicates the reductant tank heater control circuit is open for greater than 4 s.

OBDII Code P20B9 GMC - Reductant Heater 1 Control Circuit - AutoCodes.com
P20B9 GMC Code - Reductant Heater 1 Control Circuit

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Code P20B9 GMC comments

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