P2AE3 reports a break in the pumping current lead of the bank 1 intake oxygen sensor, pin 1 of a Bosch LSU 4.9 (APE/IP). Through this wire the ECM drives current into the pump cell while the Nernst cell is kept on its set point; Ford's patent US9441564B2 explains that the size of that current reflects the oxygen share of the charge, from which the EGR dilution is calculated. With the lead open, no current flows and the reading freezes. For the exhaust twin P2237 Ford detects this when reference-current pulses shift lambda by 0.05 or less within 20 s. In the intake, where the gas always stays lean, such a test would have to rely on EGR changes instead; no manufacturer publishes P2AE3 to confirm how. P2AE4/P2AE5 are low/high, P2AE6 the open return, P2AEC bank 2.
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
- EGR runs without sensor feedback or is switched off
Most likely causes
- Pump current lead (pin 1) broken
- Sensor plug loose or not latched
- Pump cell inside the sensor open
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It affects emissions.
What each character of P2AE3 means
- P: Powertrain: engine and transmission
- 2: Generic code: same on every make
- A: Hybrid or air and fuel
- E3: Specific fault in that system
Frequently asked questions
Can I keep driving with code P2AE3?
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 P2AE3?
The most common causes are: pump current lead (pin 1) broken; sensor plug loose or not latched; pump cell inside the sensor open.
Related codes
- P2AE4Intake Air O2 Sensor Pumping Current Circuit Low Bank 1
- P2AE5Intake Air O2 Sensor Pumping Current Circuit High Bank 1
- P2AE6Intake Air O2 Sensor Negative Current Control Circuit Open Bank 1
- P2AECIntake Air O2 Sensor Pumping Current Circuit Open Bank 2
- P2AE0Intake Air O2 Sensor Pumping Current Trim Circuit Open Bank 1
- P2237O2 Sensor Positive Current Control Circuit/Open (Bank 1 Sensor 1)
Sources
- patents.google.com: en
- newtonnet.co.uk: fordobd2012
- 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.