Error code

OBD2 P0411

OBD2P0411
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.

What it means

Secondary Air Injection System Incorrect Flow Detected.

Severity

moderateCan drive, but may experience reduced engine performance and noise from the AIR pump.

Summary

Code P0411 indicates an issue with the secondary air injection (AIR) system where there is incorrect flow detected by the pressure sensor in the exhaust system.

Symptoms

  • Malfunction Indicator Light (MIL) is on
  • Possible reduced engine power
  • Potential noises from the AIR pump

Common Causes

  • High resistance in connections/relay contacts to A.I.R. Pump Relay
  • Failed A.I.R. Pump
  • Failed A.I.R. System Pressure Sensor or BARO Sensor
  • Failed PCM (less likely)

Diagnosis

  1. Check for any technical service bulletins (TSBs) related to your vehicle.
  2. Inspect connections and wiring of A.I.R. Pump Relay for burn spots or corrosion.
  3. Bypass the A.I.R. Pump Relay with a jumper wire to test if the pump runs.
  4. Replace the relay if necessary and clear codes, then check if P0411 returns.
  5. Test the A.I.R. System Pressure Sensor circuit using a fused jumper wire.

Fixes

  • Inspect and clean or replace faulty connections/relay contacts to A.I.R. Pump Relay.
  • Replace the failed A.I.R. Pump if necessary.

FAQ

What does P0411 mean?

P0411 indicates incorrect flow in the secondary air injection system, detected by a pressure sensor.

How do I diagnose P0411?

Start with checking connections and relays, then test the A.I.R. Pump and Pressure Sensor circuits.

View source

Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.

More OBD2 codes

All OBD2 codes →Search more codes →