Powertrain, generic (extended)

P2B93 Wastegate Position Sensor A Exceeded Learning Limit

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P2B93 concerns the learned closed position of electric wastegate A. The computer periodically drives the valve onto its seat and stores the sensor value found there; Ford's patent US9243553B2 explains why: linkage length drifts with temperature and the reference must be refreshed. GM documents the code for the 2.7L L3B (19OBDG03D) and in the 2025 table 25OBDG03B: it fails when the raw closed position learned is above 85 %, or when no valid closed position has ever been learned while the engine runs above 1000 rpm with a stable valve and coolant at least 80 degrees Celsius. It is Type A with one trip. The usual reasons are a worn seat, a bent or stretched linkage or a replaced charger not yet adapted; this differs from P2B81, which judges how the valve follows.

Likely causes

Wastegate linkage bent, stretched or wrongly adjusted
Wastegate flap or seat worn so the valve travels too far
Turbocharger or actuator replaced and relearn not completed

Symptoms

  • MIL in the first trip
  • Boost slightly low because the valve does not fully close

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–2,500
Time0.5–5 h

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

Parts involved

wastegate position sensor awastegate actuatorecm

Related codes

P2B94P2B81P003AP2AB7P0244

References: gsi.ext.gm.com, gsi.ext.gm.com, patents.google.com.