P2629 moderate

O2 Sensor Pumping Current Trim Circuit Open Bank 2 Sensor 1

The P2629 code means the vehicle's onboard diagnostic system has detected: O2 Sensor Pumping Current Trim Circuit Open Bank 2 Sensor 1. This is a moderate severity code.

My Garage →

Keep driving?: Short distances only
DIY difficulty: moderate
Estimated cost: $150 - $500 (parts and labor)

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Common Symptoms

Check engine light on
Bank 2 fuel trim abnormal
Reduced fuel economy
Possible rough idle

Probable Causes (Ranked by Likelihood)

Failed bank 2 wideband oxygen sensor Very High
Open wiring in bank 2 O2 sensor circuit High
Corroded bank 2 O2 sensor connector Moderate
ECM bank 2 O2 driver failure Low

Step-by-Step Diagnostic Procedure

Check bank 2 O2 sensor connector and wiring
Measure sensor heater resistance
Test sensor signal response
Compare bank 2 fuel trims to bank 1

Frequently Asked Questions

Why does my V6/V8 have separate bank codes?

V-configuration engines have two exhaust banks. Each bank has its own O2 sensor for independent fuel trim control. Bank 2 is the side that does not contain cylinder 1.

Can I drive with only bank 1 sensor working?

The engine will run but bank 2 will operate in open loop, using default fuel maps instead of sensor feedback. Fuel economy and emissions will suffer.

Should I replace both bank sensors at the same time?

If one sensor has failed from age, the other is likely near end of life too. Replacing both ensures consistent performance and avoids a return trip for the second one.