P2AE9: Intake Air O2 Sensor Pumping Current Trim Circuit Open Bank 2

P2AE9 is the bank 2 version of the open trim circuit: the line from the ECM to the calibration resistor of the second intake air oxygen sensor has no continuity. A separate sensor for bank 2 only makes sense where each cylinder bank draws its charge or EGR through its own path; nobody has published a vehicle that uses P2AE9. The logic follows the exhaust analog P2629, which Ford sets for Bosch probes when the pumping current in air remains too high during a fuel cut-off event; Saab rates the bank 1 twin P2626 as Type B. As the Bosch datasheet explains, the resistor in the plug fixes the sensor's characteristic curve, so a broken trim lead leaves the reading of that bank uncalibrated. A pin pushed back in the connector is a frequent finding. P2AEA/P2AEB are low/high, P2AE0 bank 1.

Bank 2 is the side without cylinder 1, so it only exists on V or boxer engines.

Symptoms

• Check engine light on
• EGR on bank 2 reduced or without feedback

Most likely causes

• Trim contact pushed back in the plug
• Trim lead broken, often near the hot exhaust of bank 2
• Calibration resistor in the sensor connector open

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 continuity of the wire between the component and the control module.
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 P2AE9 means

• P: Powertrain: engine and transmission
• 2: Generic code: same on every make
• A: Hybrid or air and fuel
• E9: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2AE9?

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 P2AE9?

The most common causes are: trim contact pushed back in the plug; trim lead broken, often near the hot exhaust of bank 2; calibration resistor in the sensor connector open.

Related codes

• P2AEAIntake Air O2 Sensor Pumping Current Trim Circuit Low Bank 2
• P2AEBIntake Air O2 Sensor Pumping Current Trim Circuit High Bank 2
• P2AE0Intake Air O2 Sensor Pumping Current Trim Circuit Open Bank 1
• P2AECIntake Air O2 Sensor Pumping Current Circuit Open Bank 2
• P2629O2 Sensor Pumping Current Trim Circuit/Open (Bank 2 Sensor 1)

Sources

• newtonnet.co.uk: fordobd2012
• saabwisonline.com: dtc p2237 p2239 p2243 p2251 or p2626
• bosch-motorsport.com: Data Sheet 69034379 Lambda Sensor LSU 4.9
• law.cornell.edu: 13 CCR 1968.2

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.