OBD Guide

P1128

MAF Sensor Out Of Self Test Range./KOER Not Able To Complete KOER Aborted

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

Symptoms

  • Rough engine idling
  • Increased fuel consumption
  • Loss of engine power
  • Stalls at idle
  • Check Engine light comes on

Causes

  • MAF sensor malfunction
  • Contamination of the sensor element of the air flow sensor
  • Problems with the sensor electrical circuit
  • Air leaks after mass air flow sensor
  • Problems with the sensor connector

How to Fix

  1. Check the condition and cleanliness of the air flow sensor
  2. Check the electrical circuit of the sensor for opens and short circuits
  3. Check the MAF connector for oxidation and damage.
  4. Check the system for air leaks
  5. If necessary, replace the mass air flow sensor

Related codes

Error P1128 by Vehicle Brand