Powertrain, generic (extended)

P2AE3 Intake Air O2 Sensor Pumping Current Circuit Open Bank 1

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

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.

Likely causes

Pump current lead (pin 1) broken
Sensor plug loose or not latched
Pump cell inside the sensor open

Symptoms

  • Check engine light on
  • EGR runs without sensor feedback or is switched off

Repair estimate

DifficultyMediumDIY possible
Parts and labour€0–350
Time0.3–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

intake air o2 sensor b1wiring harnessecm

Related codes

P2AE4P2AE5P2AE6P2AECP2AE0P2237

References: patents.google.com, newtonnet.co.uk, bosch-motorsport.com, law.cornell.edu.