P2236 moderate

O2 Sensor Pumping Current Circuit Circuit High (Bank 1 Sensor 1)

The P2236 code means the vehicle's onboard diagnostic system has detected: O2 Sensor Pumping Current Circuit Circuit High (Bank 1 Sensor 1). This is a moderate severity code.

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Keep driving?
Short distances only
DIY difficulty
moderate
Estimated cost
$100 - $400 (parts and labor)
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Common Symptoms

  • Check Engine Light on
  • Poor fuel economy
  • Engine running rich or lean
  • Failed emissions test
  • Rough idle or hesitation

Probable Causes (Ranked by Likelihood)

  • Failed wideband O2 sensor (Bank 1 Sensor 1) Very High
  • Damaged O2 sensor wiring or connector High
  • Exhaust leak near the O2 sensor Moderate
  • ECM O2 sensor driver circuit fault Low

Step-by-Step Diagnostic Procedure

  1. Read O2 sensor Bank 1 Sensor 1 data on scan tool

  2. Inspect O2 sensor wiring and connector for damage

  3. Check for exhaust leaks near the sensor location

  4. Replace O2 sensor if readings are outside specification

Frequently Asked Questions

What is an O2 sensor pumping current?

Wideband (air-fuel ratio) O2 sensors use a pumping current to precisely measure the oxygen content in exhaust gas. This is more accurate than traditional narrowband O2 sensors.

Can I use a universal O2 sensor for this?

Wideband O2 sensors are more complex than narrowband sensors. It is recommended to use an OEM or direct-fit replacement rather than a universal sensor to ensure proper operation.

How long do wideband O2 sensors last?

Wideband O2 sensors typically last 60,000 to 100,000 miles. Contamination from oil burning, coolant leaks, or fuel additives can shorten their lifespan.

Sources

This page is built from documented references. Verify against your own service info before repair work.

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