P2431 Code - Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1
Quick Answer
The Secondary Air Injection (AIR) System aids in the reduction of hydrocarbon exhaust emissions during a cold start-up. Common causes include Faulty AIR Pressure Sensor, AIR Pressure Sensor harness is open or shorted, AIR Pressure Sensor circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P2431 indicates Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1.
- Common causes
- Common causes include Faulty AIR Pressure Sensor, AIR Pressure Sensor harness is open or shorted, AIR Pressure Sensor circuit poor electrical connection.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P2431 Description
The Powertrain Control Module (PCM) activates the AIR system by simultaneously supplying grounds to the AIR pump and the AIR valve relays. This action closes the relays' internal contacts. The AIR pump and the AIR control solenoid valve/pressure sensor assembly are in turn energized, the pump runs and the control/shut-off valve opens.
The AIR pump sends pressurized fresh air into the pipes/hoses through the open control/shut-off valve, and into the exhaust manifold. The extra air accelerates the catalyst operation, helping it to reach operating temperature faster. The AIR pump remains ON for a short period of time after the control/shut-off valve is commanded OFF. When the AIR pump is commanded OFF it will not run or be activated until the next vehicle start. When the AIR system is inactive, the closed AIR control/shut-off valve prevents air/exhaust flow in either direction.
The AIR system pressure sensor is used to monitor pressure at the AIR control solenoid valve/pressure sensor assembly inlet during the commanded ON/OFF states.
What are the Possible Causes of the DTC P2431?
- Faulty AIR Pressure Sensor
- AIR Pressure Sensor harness is open or shorted
- AIR Pressure Sensor circuit poor electrical connection
How to Fix the DTC P2431?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P2431 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Information for Specific Makes
- P2431 Audi — Secondary Air Injection System Air Flow/Pressure Bank 1 Sensor Circuit Range/Performance
- P2431 Buick — Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1
- P2431 Cadillac — Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1
- P2431 Chevrolet — Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1
- P2431 Dodge — Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1
- P2431 GMC — Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1
- P2431 Lexus — Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1
- P2431 Pontiac — Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1
- P2431 Saturn — Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1
- P2431 Scion — Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1
- P2431 Toyota — Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1
- P2431 Volkswagen — Secondary Air Injection System Air Flow/Pressure Bank 1 Sensor Circuit Range/Performance
Frequently Asked Questions about P2431 Code
No Frequently Asked Questions about P2431 Code found.
Discuss the causes and fixes for P2431 OBDII Code
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My 08 envoy does same thing. Replaced every part in the secondary air injection system
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The P2431 code (Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance - Bank 1) means that the airflow or pressure sensor in the Secondary Air Injection (SAI) system is reading values outside the expected range.
Since you’ve already replaced every part in the SAI system, but the code keeps coming back, here are a few things to check:
Possible Causes of P2431 Reoccurring:
- Faulty Air Injection Pressure Sensor – Even though parts were replaced, a defective or aftermarket sensor could still cause incorrect readings.
- Wiring or Connector Issue – The sensor wiring may be damaged, corroded, or loose, causing erratic signals to the ECM.
- PCM Software Update Needed – Some GM vehicles have known software issues related to the SAI system. A dealership reflash may be required.
- Exhaust Backpressure Issues – If the exhaust is restricted (partially clogged catalytic converter), it could affect airflow readings.
- Vacuum Leak or Hose Connection Issue – Double-check all hoses and fittings for cracks or improper connections.
What You Can Do:
✅ Check & Test Wiring – Inspect the air injection pressure sensor connector and wiring for corrosion, damage, or poor connections.
✅ Scan Live Data – Use an advanced scanner to monitor the air injection pressure sensor values during startup (SAI system only runs at cold start). If readings are erratic, the sensor or wiring could be at fault.
✅ Check for PCM Updates – Contact a GM dealer or check online for any ECM reflash or software updates related to the SAI system.
✅ Verify Exhaust Flow – Ensure there are no restrictions in the exhaust system that could affect airflow detection.Since your Envoy runs fine, this is likely a sensor, wiring, or PCM issue rather than a mechanical failure. If you replaced parts with aftermarket components, consider using OEM as some aftermarket sensors can cause range/performance issues.
Let us know what you find!
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So perhaps slight oversight on replacing air filter. Replaced air filter today. Old one smelled like gas probably due to Maf code and system running lean condition adding fuel by the fuel trim reading when that was a problem. P2431 code was cleared today. So far has not returned. Also cleaned mac while air filter.
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Have not replaced any parts. Had a passat turbo and the plastic hoses broke all the time from air pump. but this seem ok.
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