P20AA – Reductant Injection Air Pressure Control Valve Stuck Open

P20AA Possible Causes

  • Faulty air injection pressure control valve
  • Open or shorted air injection pressure control valve circuit
  • Poor electrical connection in the air injection pressure control valve circuit

What Does It Mean?

How to Fix Code P20AA

Check the “possible causes” listed above. Visually inspect the related wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

P20AA Possible Symptoms

Check engine light on (or service engine soon warning light)

P20AA Meaning

Air injection pressure control valve stuck open is the generic description for code P20AA, but the manufacturer may have a different description

P20AB – Reductant Injection Air Pressure Control Valve Stuck Closed

P20AB Possible Causes

  • Faulty reductant injection air pressure control valve
  • Reductant injection air pressure control valve circuit open or shorted
  • Poor electrical connection in reductant injection air pressure control valve circuit

What Does It Mean?

How to Fix Code P20AB

Check the “possible causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P20AB Possible Symptoms

Engine light on (or service engine soon warning light)

P20AB Meaning

Reductant injection air pressure control valve stuck closed is the generic description for code P20AB, but the manufacturer may have a different description.

P20AC – Reduction Unit Temperature Sensor Circuit

P20AC Possible Causes

  • Faulty reductant metering unit temperature sensor
  • Reductant metering unit temperature sensor harness is open or shorted
  • Poor electrical connection in reductant metering unit temperature sensor circuit

What Does It Mean?

How to Fix Code P20AC

Check the “possible causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P20AC Possible Symptoms

Check engine light illuminated (or service engine soon warning light)

P20AC Meaning

Reductant metering unit temperature sensor circuit is the generic description for code P20AC, but the manufacturer may have a different description

P20AD – Range/Performance of the Reduction Unit Temperature Sensor Circuit

P20AD Possible Causes

  • Faulty transmission fluid temperature sensor
  • Transmission fluid temperature sensor harness is open or shorted
  • Poor electrical connection in transmission fluid temperature sensor circuit

What Does It Mean?

How to Fix Code P20AD

Check the “possible causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P20AD Possible Symptoms

Check Engine Light on (or Service Engine Soon Warning Light)

P20AD Meaning

Transmission Fluid Temperature Sensor Circuit Range/Performance is the generic description for P20AD code, but the manufacturer may have a different description.

P20AE – Lower Reductant Unit Temperature Sensor Circuit

P20AE Possible Causes

  • Faulty transmission fluid temperature sensor
  • Transmission fluid temperature sensor circuit open or shorted
  • Poor electrical connection in transmission fluid temperature sensor circuit

What Does It Mean?

How to Fix Code P20AE

Check the “possible causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P20AE Possible Symptoms

Check engine light illuminated (or service engine soon warning light)

P20AE Meaning

Transmission fluid temperature sensor circuit low is the generic description for code P20AE, but the manufacturer may have a different description

P20AF – High Reductant Unit Temperature Sensor Circuit

P20AF Possible Causes

  • Faulty reduction unit temperature sensor
  • Reduction unit temperature sensor wiring harness open or shorted
  • Poor electrical connection in reduction unit temperature sensor circuit

What Does It Mean?

How to Fix Code P20AF

Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P20AF Possible Symptoms

Check Engine Light on (or Service Engine Soon warning light)

P20AF Meaning

High Reduction Unit Temperature Sensor Circuit is the generic description for code P20AF, but the manufacturer may have a different description.

P20B0 – Intermittent/Erratic Reducer Measuring Unit Temperature Sensor Circuit

How to Fix Code P20B0

Check the “Possible Causes” listed above. Visually inspect the wiring harness and associated connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P20B0 Technical Notes

  • – Defective reduction unit temperature sensor
  • – Reduction unit temperature sensor wiring harness is open or short-circuited
  • – Poor electrical connection in the reduction unit temperature sensor circuit

What Does It Mean?

P20B0

Possible Symptoms

Check engine light on (or service engine soon warning light)

P20B0 Meaning

Intermittent/irregular reduction unit temperature sensor circuit is the generic description for code P20B0, but the manufacturer may have a different description.

P20B1 – Reductant Heater Coolant Control Valve Circuit / Open

P20B1 Possible Causes

  • Faulty reductant heater coolant control valve
  • Reductant heater coolant control valve circuit open or shorted
  • Poor electrical connection in reductant heater coolant control valve circuit

What Does It Mean?

How to Fix Code P20B1

Check the “possible causes” listed above. Visually inspect related wiring harnesses and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P20B1 Possible Symptoms

Illuminated engine light (or service engine soon warning light)

P20B1 Meaning

Reductant heater coolant control valve circuit/open is the generic description for code P20B1, but the manufacturer may have a different description

P20B2 – Performance of the Coolant Control Valve for the Gearbox Heater

P20B2 Possible Causes

  • Faulty reductant heater coolant control valve
  • Reductant heater coolant control valve harness is open or shorted
  • Poor electrical connection in reductant heater coolant control valve circuit

What Does It Mean?

How to Fix Code P20B2

Check the “possible causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P20B2 Possible Symptoms

Check engine light on (or service engine soon warning light)

P20B2 Meaning

Reductant heater coolant control valve performance is the generic description for code P20B2, but the manufacturer may have a different description.

P20B3 – Lower Reducer Heater Coolant Control Valve Circuit

P20B3 Possible Causes

  • Faulty reductant heater coolant control valve
  • Reductant heater coolant control valve harness is open or shorted
  • Poor electrical connection in reductant heater coolant control valve circuit

What Does It Mean?

How to Fix Code P20B3

Check the “possible causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P20B3 Possible Symptoms

Check engine light on (or service engine soon warning light)

P20B3 Meaning

Reductant heater coolant control valve circuit is the generic description for code P20B3, but the manufacturer may have a different description.