OBD Guide

P203C

Reductant Level Sensor A Circuit Low

P203C is an OBD-II diagnostic trouble code meaning: Reductant Level Sensor A Circuit Low. Common causes: reagent level sensor malfunction, open or short circuit in the sensor circuit. Estimated repair cost: $50–133.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$50–133 (est.)

Symptoms

  • Check Engine Light Is On
  • Reduced engine power
  • Low AdBlue level message (even with a full tank)
  • Increased fuel consumption
  • Possible problems starting the engine

Causes

  • Reagent level sensor malfunction
  • Open or short circuit in the sensor circuit
  • Poor contact in the sensor connector
  • Problems with the SCR control unit
  • Corroded contacts or damaged wiring

How to Fix

  1. Check AdBlue level
  2. Inspect the sensor connector and wiring for damage.
  3. Check the resistance and voltage in the sensor circuit
  4. If necessary, replace the reagent level sensor
  5. Check and update the SCR control unit software

Related codes

Error P203C by Vehicle Brand

FAQ

What does the P203C code mean?

P203C is an OBD-II diagnostic trouble code that indicates: Reductant Level Sensor A Circuit Low

What causes a P203C error code?

The most common causes of P203C include: Reagent level sensor malfunction; Open or short circuit in the sensor circuit; Poor contact in the sensor connector; Problems with the SCR control unit.

How do I fix a P203C diagnostic trouble code?

To fix P203C: Check AdBlue level. Inspect the sensor connector and wiring for damage.. Check the resistance and voltage in the sensor circuit. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P203C?

Yes, but get it checked soon

How much does it cost to fix P203C?

The estimated repair cost for P203C is $50–133. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat