P2C63: O2 Sensor Pumping Current Trim Circuit Low Bank 1 Sensor 3

The wide-band oxygen sensor on bank 1 sensor 3 reports a pumping current trim circuit low condition. Lambda regulation accuracy is impaired.

Medium severity. Can I keep driving?Yes, you can normally drive in moderation, but get it repaired soon: you will use more fuel and the catalytic converter can be damaged over time.

Bank 1 is the side of the engine with cylinder 1. Inline engines only have this bank.

Symptoms

Check engine light on
Increased fuel consumption
Possible rough idle or hesitation
Failed emissions test

Most likely causes

Trim wire shorted to ground
Internal short in pump cell trim
Connector pins corroded - high contact resistance

What to check, in order

Start with the simplest. You can tick off each step.

Check the wiring and connector of the sensor indicated
With the connector unplugged, check whether the signal wire is making contact with ground.
Look for exhaust leaks
Check the signal in live data with the engine warm
Check the fuse and the heater resistance if the code mentions it
Replace the sensor if it has power and does not respond

Good to know

Repair difficulty: medium
It affects emissions.

What each character of P2C63 means

P: Powertrain: engine and transmission
2: Generic code: same on every make
C: Subsystem depends on the code range
63: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2C63?

Yes, you can normally drive in moderation, but get it repaired soon: you will use more fuel and the catalytic converter can be damaged over time.

What causes code P2C63?

The most common causes are: trim wire shorted to ground; internal short in pump cell trim; connector pins corroded - high contact resistance.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.