OBD Guide

P1291

No Temperature Rise Seen From Intake Air Heater

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$17–89 (est.)

Symptoms

  • Difficulty starting the engine in cold weather
  • Increased fuel consumption
  • Increased emissions
  • Check Engine Light Is On
  • Reduced engine power in cold conditions

Causes

  • Intake air heater malfunction
  • Open or short circuit in the heater circuit
  • Heater relay problems
  • Intake air temperature sensor malfunction
  • Problems with the engine control unit

How to Fix

  1. Check the power and ground of the heater circuit
  2. Check heater resistance
  3. Check the operation of the heater relay
  4. Check intake air temperature sensors
  5. If necessary, replace the intake air heater

Related codes

Error P1291 by Vehicle Brand