O2 Sensor Negative Current Control Circuit High (Bank 2, Sensor 1)
The P2252 code means the vehicle's onboard diagnostic system has detected: O2 Sensor Negative Current Control Circuit High (Bank 2, Sensor 1). This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $150 - $400 (parts and labor)
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Common Symptoms
- Check Engine Light on
- Engine running rich on Bank 2
- Poor fuel economy
- Black exhaust smoke
- Failed emissions test
Probable Causes (Ranked by Likelihood)
- Failed wideband O2 sensor with high negative pump cell current Very High
- Short to voltage in the negative current control wiring High
- Sensor contamination from oil or coolant Moderate
- Clogged catalytic converter causing abnormal backpressure Moderate
- ECM negative current driver outputting high Low
Step-by-Step Diagnostic Procedure
-
Read Bank 2 Sensor 1 negative pump cell current data
-
Check for wiring shorts to voltage in the negative current circuit
-
Inspect the sensor for contamination or physical damage
-
Check for exhaust restrictions on Bank 2
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Replace the wideband O2 sensor if internal failure is confirmed
Frequently Asked Questions
What causes high negative pump cell current?
High negative current indicates the sensor is trying to over-compensate, typically for a rich exhaust condition, by pumping excess oxygen out of the measurement cell.
Can engine oil burning cause P2252?
Yes, if the engine is burning oil, the oil residue can contaminate the wideband sensor element and cause erratic pump cell current readings.
How do I prevent wideband sensor contamination?
Address any oil consumption issues, fix coolant leaks, and avoid using silicone-based gasket sealers near the intake or exhaust, as silicone can permanently damage O2 sensors.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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