P1434 — Volkswagen — Secondary Air Injection Pump Relay Circuit Short To B+

P1434 (Volkswagen): Secondary Air Injection Pump Relay Circuit Short To B+ — what it means, the affected system and what to check before replacing parts.

Meaning, symptoms, causes and checks

Secondary Air Injection Pump Relay Circuit Short To B+. Source catalogue definition; confirm applicability using vehicle service information.

Affected system: Powertrain

Symptoms

  • Check Engine light illuminated
  • Increased exhaust emissions during cold start
  • Failure of vehicle emissions test
  • Audible noise or lack of operation from the secondary air pump

Possible causes

  • Secondary air injection pump relay stuck closed
  • Short circuit to battery positive in the relay control wiring
  • Faulty engine control module
  • Corroded or damaged relay socket terminals

What to check

  • Inspect the secondary air pump relay for internal welding of contacts
  • Test the relay control circuit for a short circuit to battery positive voltage using a multimeter
  • Examine the wiring harness between the ECU and the relay for chafing or insulation damage
  • Verify the operation of the relay coil and switching contacts
  • Check the engine control module output pin for internal faults