Powertrain, generic (extended)

P2AE8 Intake Air O2 Sensor Negative Current Control Circuit High Bank 1

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P2AE8 reports that, on bank 1's intake air oxygen sensor, the negative current control line sits above its intended level. For the bias on this return to climb towards battery voltage, something must feed it: most often the heater supply sharing the six-pin plug, sometimes condensate in a connector that collects moisture from the intake air. With the reference raised, the ECM loses its anchor for regulating the Nernst cell and discards the oxygen value. Ford handles a VM lead shorted to battery on exhaust probes under P0132, and the Bosch LSU 4.9 sheet lists the trim, pump and return pins side by side, which shows how close these faults sit. No manufacturer documents P2AE8 publicly. P2AE6 is the open fault, P2AE7 the low one, P2AE5 the high fault on the pump lead, P2AF1 bank 2.

Likely causes

Return lead shorted to the heater supply
Condensate inside the sensor connector
Internal short between heater and cell

Symptoms

  • Check engine light on
  • EGR reduced, NOx may rise

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

P2AE6P2AE7P2AE5P2AF1P2253

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