P2437 - Secondary Air Injection System Air Flow/Pressure Sensor Circuit Low Bank 2
The P2437 code indicates that the Powertrain Control Module (PCM) 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 injects 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 blocked SAI system.
1. Most Common Causes
- Faulty or worn secondary air injection (SAI) flow/pressure sensor
- Sensor wiring shorted to ground or open circuit
- Corroded, oxidized, or damaged sensor connector pins
- Failed secondary air injection pump or insufficient pump flow
- SAI control valve stuck closed or obstructed
- Blocked, pinched, or disconnected secondary air system hoses or pipes
- Blown secondary air pump fuse
- Intermittent wiring harness fault due to chafing or heat damage
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Failed emissions test
- Rough idle or hesitation during cold start
- Possible reduced engine performance
3. 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 system components (pump, hoses, valves) for damage, blockages, or leaks.
Step 3: Test the air flow/pressure sensor voltage and ground circuits with a multimeter; compare to manufacturer specifications.
Step 4: Check the sensor connector for corrosion, bent pins, or loose connections.
Step 5: If wiring and connections are good, replace the air flow/pressure sensor on Bank 2.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is generally safe to drive short distances, but the vehicle may fail an emissions test and could experience rough idle or reduced performance. Prolonged driving may cause additional issues if the SAI system is blocked.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and sensor replacement, but can be higher if the SAI pump or other components need repair.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.