OBD Guide

P1418

Secondary Air Injection System Relay 'A' Control Circuit High

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$17–56 (est.)

Symptoms

  • Check Engine Light Is On
  • Deterioration of engine performance when cold
  • Increased emissions
  • Possible misfires when warming up
  • Noise from the secondary air pump

Causes

  • Short circuit to positive in the relay control circuit
  • Faulty secondary air relay
  • Wiring harness damage
  • Problems with the engine control unit
  • Corrosion of contacts or connectors

How to Fix

  1. Check the integrity of the system wiring harness
  2. Test secondary air relay
  3. Check control circuit voltage
  4. Replace relay if necessary
  5. Clean or replace damaged connectors

Related codes

Error P1418 by Vehicle Brand