What does code P1433 mean?

Q: What does code P1433 mean?

Secondary Air Injection Pump Relay Circuit Open. The secondary air injection (SAI) system pumps fresh air into the exhaust during cold starts to help the catalytic converter light off quickly, and the engine control module (ECM) commands a relay to power the electric air pump. Code P1433 means the ECM detected an open circuit on the relay control circuit, so it cannot confirm the relay coil is receiving the command signal. This is an electrical fault in the relay control wiring or the relay itself, not a mechanical failure of the air pump.

DTC codes / Volkswagen codes / P1433

P1433 · VolkswagenSecondary Air Injection Pump Relay Circuit Open

The secondary air injection (SAI) system pumps fresh air into the exhaust during cold starts to help the catalytic converter light off quickly, and the engine control module (ECM) commands a relay to power the electric air pump. Code P1433 means the ECM detected an open circuit on the relay control circuit, so it cannot confirm the relay coil is receiving the command signal. This is an electrical fault in the relay control wiring or the relay itself, not a mechanical failure of the air pump.

SystemPowertrain

Code typeVolkswagen specific

SeverityLow

Fix difficultyIntermediate

AreaAuxiliary emission controls

Guidance is general and written for Volkswagen vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.