Powertrain, generic (extended)

P2AE7 Intake Air O2 Sensor Negative Current Control Circuit Low Bank 1

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P2AE7 is set when the virtual-ground return of the bank 1 intake oxygen sensor is pulled below its bias. In operation this lead sits roughly 2.5 V above chassis, as Saab's 2010 9-5 documents for its wide-band probe; a wire touching the engine block, a bracket or the intake pipe drags it towards zero. The pump cell then has hardly any room to work, and both the measured oxygen share and the EGR rate derived from it become meaningless. Ford counts a grounded VM lead among the faults that set P0131 on its exhaust probes. No manufacturer documents P2AE7 itself, so this rests on CARB's range-check duty and the Bosch pin layout. P2AE6 is the open return, P2AE8 the high case, P2AE4 the low fault on the pump lead, P2AF0 bank 2.

Likely causes

Return lead chafed against engine or bracket
Internal short of the common electrode to ground
Bias source in the ECM faulty

Symptoms

  • Check engine light on
  • EGR cut back, possibly higher NOx

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

P2AE6P2AE8P2AE4P2AF0P2252

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