P22BA: O2 Sensor Positive Current Control Circuit High (Bank 2 Sensor 2)

P22BA is set when the pump-current (positive current control) wire of the bank 2 downstream wide-band probe is held above its normal bias, typically through contact with the heater supply or a damaged connector letting battery voltage in. No maker documents this code publicly. Related evidence comes from bank 1 and the front sensors: GM names P22AD for the 3.0 Duramax LM2 in a harness-chafing bulletin, Saab measures about 2.8 V on the pump pins of a healthy upstream probe and rates P2239 as Type B, and Ford reports upstream shorts to power as P0132. The code only applies to dual-bank engines with a wide-band probe after each catalyst. P22B8 is the open, P22B9 the low code, P22AD bank 1. Expect the warning lamp.

Bank 2 is the side without cylinder 1, so it only exists on V or boxer engines. Sensor 2 is the sensor after the catalytic converter.

Symptoms

• Check engine light
• Bank 2 downstream oxygen value implausibly high

Most likely causes

• Pump-current wire shorted to the heater feed or battery voltage
• Heater-to-pump-cell leakage inside the sensor
• Faulty sensor interface in the ECM

What to check, in order

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

1. Check the wiring and connector of the sensor indicated
2. Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
3. Look for exhaust leaks
4. Check the signal in live data with the engine warm
5. Check the fuse and the heater resistance if the code mentions it
6. Replace the sensor if it has power and does not respond

Good to know

• Repair difficulty: medium
• It affects emissions.

What each character of P22BA means

• P: Powertrain: engine and transmission
• 2: Generic code: same on every make
• 2: Fuel injection
• BA: Specific fault in that system

Frequently asked questions

Can I keep driving with code P22BA?

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 P22BA?

The most common causes are: pump-current wire shorted to the heater feed or battery voltage; heater-to-pump-cell leakage inside the sensor; faulty sensor interface in the ECM.

Related codes

• P22B8O2 Sensor Positive Current Control Circuit/Open (Bank 2 Sensor 2)
• P22B9O2 Sensor Positive Current Control Circuit Low (Bank 2 Sensor 2)
• P22ADO2 Sensor Positive Current Control Circuit High (Bank 1 Sensor 2)
• P2242O2 Sensor Positive Current Control Circuit High (Bank 2 Sensor 1)

Sources

• law.cornell.edu: 13 CCR 1968.2
• saabwisonline.com: dtc p2237 p2239 p2243 p2251 or p2626
• static.nhtsa.gov: MC 10224856 0001

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.