OBD Guide

P1605

Engine Rough Idling

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$6–56 (est.)

Symptoms

  • Engine idles rough
  • Floating speed
  • Vibrations at idle
  • RPM dips
  • Possible difficulty starting

Causes

  • Throttle valve contamination
  • Throttle Position Sensor Malfunction
  • Problems with idle air control
  • Vacuum leaks
  • Ignition system malfunctions

How to Fix

  1. Check and clean the throttle valve
  2. Check the operation of the throttle position sensor
  3. Inspect the idle air control
  4. Check the system for vacuum leaks
  5. Diagnose the ignition system

Related codes

Error P1605 by Vehicle Brand