P2431

Code

LAND ROVER P — Powertrain

Secondary air injection system flow/pressure sensor - track / circuit performance, bank 1

Brand: LAND ROVER

Type: P — Powertrain

Views: UK: 9 EN: 31 RU: 24

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Page language: EN

Causes

Failed or intermittent SAI flow/pressure sensor (bank 1)
Damaged, corroded, or disconnected wiring/connector to the sensor
Open/short to sensor reference or signal circuit
Faulty secondary air pump or control solenoid/valve (no flow when commanded)
Blocked, collapsed or disconnected SAI hoses or check valve
Mechanical restriction in air injection path (clogged ports or valve)

Symptoms

Malfunction Indicator Lamp (MIL/Check Engine) illuminated
Reduced or no secondary air injection during cold start leading to higher cold-start emissions
Possible rough cold start or drivability issues during warm-up
Audible SAI pump operation abnormal (no pump noise when commanded or unusually loud)
Failed emissions test

What to check

Read and record freeze frame data and all stored/related DTCs
Perform an active test (command SAI pump and/or valve) with a diagnostic tool and observe response
Monitor live data for SAI flow/pressure sensor voltage or raw value while commanding the pump
Visually inspect SAI pump, hoses, check valve and connections for damage, disconnection or blockages
Inspect sensor and harness for corrosion, bent pins, damaged insulation or water ingress
Back-probe sensor connector to verify reference voltage (typically 5V), ground and signal behavior during pump command

Signal parameters

Sensor reference: typically 5 V reference (verify with OEM data)
Sensor signal: generally low at rest and changes when pump is running; expect a measurable change (example nominal range ~0.5–4.5 V depending on sensor design) — consult vehicle service data for exact values
Expected change when pump commanded: signal should move noticeably from idle (example: >0.5 V change)
Pump current draw: typically between ~2–10 A when operating (varies by model)
Valve duty cycle or command: 0–100% depending on control strategy — verify with scanner

Diagnostic algorithm

Connect a factory-level or equivalent diagnostic scanner; read and record DTCs and freeze frame data
Clear the code, then perform a road or cold-start test to see if code returns and capture live data
Command the SAI pump/valve ON via diagnostic tool; confirm pump runs (audible/feel) and monitor sensor signal for appropriate change
If pump does not run when commanded, check pump power and ground at the pump connector; verify control wiring from ECM to pump/solenoid
If pump runs but sensor signal does not change, back-probe sensor connector: verify 5V reference present, good ground and signal output. If reference or ground missing, trace/repair wiring to ECM
Perform continuity and resistance checks between sensor connector and ECM to identify opens/shorts. Repair damaged wiring or connectors.
Inspect and remove SAI hoses, check valve and related plumbing; verify airflow path and that non-return valve is not stuck closed. Replace or clear blockages as needed
Measure pump current while running. Excessive or no current suggests pump electrical or mechanical failure—replace pump if confirmed
If wiring and components test good but signal is erratic, replace the SAI flow/pressure sensor (bank 1) and retest
After repairs, clear codes and repeat tests to confirm the fault is resolved. If code persists with all circuits confirmed good, consult vehicle-specific technical service information for ECM testing or update

Likely causes

Failed SAI flow/pressure sensor
Wiring harness damage or poor connector contact at sensor/ECM
Blocked or leaking SAI hoses or stuck check valve
Failed SAI pump or control valve/solenoid

Fault status

⚠️ Status

P2431: Secondary air injection flow/pressure sensor circuit/performance fault (Bank 1). Check sensor, wiring/connectors, pump and air path for faults or blockages.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-2.5 hours

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P2431 — Secondary air injection system flow/pressure sensor - track / circuit performance, bank 1