P2437 - Secondary Air Injection System Air Flow/Pressure Sensor Circuit Low Bank 2
The P2437 code indicates that the Engine Control Module (ECM) has detected a low voltage signal from the secondary air injection (SAI) system air flow/pressure sensor on Bank 2. This sensor monitors the air flow or pressure in the SAI system, which pumps fresh air into the exhaust to reduce emissions during cold starts. A low circuit condition typically means the sensor signal is below the expected range, often due to a faulty sensor, wiring issues, or a problem with the SAI pump or its relay. This can lead to increased emissions and potential failure of emissions tests.
01. Most Common Causes
- Faulty secondary air injection pressure sensor
- Open or shorted wiring in the sensor circuit
- Corroded or loose electrical connector
- Failed secondary air injection pump or relay
- Blown fuse for the SAI system
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Failed emissions test
- Rough idle or hesitation during cold start
- Possible reduced engine performance
03. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for additional codes.
Step 2: Visually inspect the SAI pressure sensor and its wiring for damage, corrosion, or loose connections.
Step 3: Test the sensor's voltage and ground supply with a multimeter; compare to manufacturer specs.
Step 4: Check the SAI pump operation and relay; listen for pump activation during cold start.
Step 5: If all else is fine, replace the SAI pressure sensor and clear the code.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
Yes, it is generally safe to drive, but the vehicle may fail an emissions test and the Check Engine Light will remain on. It's best to diagnose and repair promptly to avoid potential drivability issues.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for parts and labor, depending on whether the sensor or pump needs replacement. DIY replacement of the sensor is often under $50.