OBD Guide

P209C

Reductant Injection Air Pressure Sensor B Circuit Low

P209C is an OBD-II diagnostic trouble code meaning: Reductant Injection Air Pressure Sensor B Circuit Low. Common causes: air pressure sensor b fault, open or short circuit in the sensor circuit. Estimated repair cost: $28–89.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$28–89 (est.)

Symptoms

  • Check Engine light comes on
  • Reduced engine power
  • Increased fuel consumption
  • Problems with the SCR (AdBlue) system
  • Increased emissions

Causes

  • Air pressure sensor B fault
  • Open or short circuit in the sensor circuit
  • Poor contact in the sensor connector
  • Problems with the engine control unit
  • Dirty or damaged wiring harness

How to Fix

  1. Check the integrity of the sensor circuit
  2. Check sensor connectors and connections
  3. Test air pressure sensor B
  4. Replace sensor if necessary
  5. Check and update ECU software if necessary

Related codes

Error P209C by Vehicle Brand

FAQ

What does the P209C code mean?

P209C is an OBD-II diagnostic trouble code that indicates: Reductant Injection Air Pressure Sensor B Circuit Low

What causes a P209C error code?

The most common causes of P209C include: Air pressure sensor B fault; Open or short circuit in the sensor circuit; Poor contact in the sensor connector; Problems with the engine control unit.

How do I fix a P209C diagnostic trouble code?

To fix P209C: Check the integrity of the sensor circuit. Check sensor connectors and connections. Test air pressure sensor B. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P209C?

Yes, but get it checked soon

How much does it cost to fix P209C?

The estimated repair cost for P209C is $28–89. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat