OBD Guide

P20F4

Reductant Consumption Too Low

P20F4 is an OBD-II diagnostic trouble code meaning: Reductant Consumption Too Low. Common causes: low adblue level in tank, reagent pump malfunction. Estimated repair cost: $28–167.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$28–167 (est.)

Symptoms

  • Check Engine light comes on
  • Reduced engine power
  • Increased fuel consumption
  • Low AdBlue level message (even with a full tank)
  • The engine may go into emergency mode

Causes

  • Low AdBlue level in tank
  • Reagent pump malfunction
  • SCR injector clogged
  • Problems with NOx sensors
  • Open circuit or wiring fault

How to Fix

  1. Check AdBlue level and top up if necessary
  2. Diagnose the reagent supply pump
  3. Check and, if necessary, clean or replace the SCR injector
  4. Scan the system for other fault codes
  5. Check the condition of wiring and connections to SCR system components

Related codes

Error P20F4 by Vehicle Brand

FAQ

What does the P20F4 code mean?

P20F4 is an OBD-II diagnostic trouble code that indicates: Reductant Consumption Too Low

What causes a P20F4 error code?

The most common causes of P20F4 include: Low AdBlue level in tank; Reagent pump malfunction; SCR injector clogged; Problems with NOx sensors.

How do I fix a P20F4 diagnostic trouble code?

To fix P20F4: Check AdBlue level and top up if necessary. Diagnose the reagent supply pump. Check and, if necessary, clean or replace the SCR injector. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P20F4?

Yes, but get it checked soon

How much does it cost to fix P20F4?

The estimated repair cost for P20F4 is $28–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat