What it means
AIR System Air Flow or Pressure Sensor Circuit Low Bank 2: the signal voltage is below the expected range. Often a short to ground or high resistance in the wiring.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The bank 2 SAI air-flow or pressure sensor measures the air injected into the exhaust and sends a signal to the control module. P2437 sets when that signal falls below the expected electrical range, commonly because the signal circuit is shorted to ground or has excessive resistance.
Common causes
Most likely first.
- Signal shorted to ground
- Connector pins corroded - high contact resistance
- Harness chafing through insulation
Symptoms
- Check-engine light on
- Rough cold start
- Reduced power or increased emissions
How to diagnose it
- Review freeze-frame data and monitor the bank 2 sensor signal during a commanded SAI pump operation to confirm it is below range.
- Inspect bank 2 sensor wiring and connector terminals for chafing, corrosion, loose pins, or a signal wire contacting ground.
- Check the bank 2 signal circuit for a short to ground and test power and ground connections using the vehicle wiring diagram.
- Measure circuit continuity and sensor response during the pump command, comparing them with the manufacturer's specification.
- If wiring and connections pass, test the bank 2 sensor for a low or failed output.
Common fixes
- Repair chafed bank 2 wiring that has exposed the signal wire to ground.
- Clean or repair corroded or loose connector terminals.
- Repair an open or high-resistance section of the bank 2 sensor circuit.
- Replace the bank 2 SAI sensor if its signal remains low with a verified circuit.
Can I keep driving?
If the engine runs normally, limited driving is usually possible, but the fault can increase emissions and cause rough cold starts. Avoid extended driving if power falls or the engine runs poorly.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.