Catalyst Temperature Sensor Low (Bank 2)
What does P0437 mean?
The P0437 code means the vehicle's onboard diagnostic system has detected: Catalyst Temperature Sensor Low (Bank 2). This is a low severity code.
Common Symptoms
- Check Engine Light illuminated
- No drivability symptoms
- Bank 2 catalyst temperature reads abnormally low
- Failed emissions test
Probable Causes (Ranked by Likelihood)
- Faulty Bank 2 catalyst temperature sensor Very High
- Open signal wire in Bank 2 sensor circuit High
- Corroded or loose Bank 2 sensor connector Moderate
- ECM Bank 2 input circuit fault Low
Step-by-Step Diagnostic Procedure
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Check Bank 2 catalyst temperature on a scan tool -- should match ambient when cold and rise with engine operation
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Inspect the Bank 2 sensor connector for corrosion
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Measure signal wire voltage at the ECM connector for Bank 2
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Check for open circuit in signal or ground wires
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Replace the sensor if wiring is confirmed good and readings remain low
Frequently Asked Questions
Can I drive with code P0437?
Yes. The low temperature reading on Bank 2 does not affect engine operation or drivability.
Is P0437 the Bank 2 version of P0427?
Yes. P0427 indicates Bank 1 catalyst temperature sensor low and P0437 is the equivalent for Bank 2.
Could a large exhaust leak cause P0437?
Yes. A significant exhaust leak on Bank 2 before the sensor can introduce cool ambient air, causing lower temperature readings even if the sensor itself is functioning properly.