Powertrain, generic (extended)

P2AB9 Wastegate Position Sensor A Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2AB9 is logged when the wastegate A position signal climbs above its valid ceiling. Typical reasons are a signal wire shorted to the sensor supply or to battery voltage, an open ground return that lets the input float upward, or an internal sensor fault. GM's ECM checks the raw position as a share of the reference: above 95 % in the 2019 L3B tables and above 99 % in the 2025 tables, each with 10 failures in 12 samples and Type A, lamp in the first trip. Ford flags it above 4.50 V for 4 s and has reflashed 2021-22 F-150 2.7L trucks (TSB 22-2357) as well as 2020-23 Explorer, 2022-23 F-150 3.5L and Expedition/Navigator (TSB 23-2353) against false settings. With the flap position unknown, boost is held back. P2AB8 is the low side, P2ABC bank 2.

Likely causes

Signal wire shorted to the sensor supply or battery voltage
Open sensor ground or corroded ground terminal
PCM calibration that sets the code falsely (Ford reflash for listed models)
Position sensor inside the electric actuator failed

Symptoms

  • Check engine light from the first trip
  • Lower power under load, boost held back
  • Powertrain fault (wrench) indicator on some Ford models

Repair estimate

DifficultyMediumDIY possible
Parts and labour€0–800
Time0.3–3 h

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

Parts involved

wastegate position sensor awiring harnessecm

Related codes

P2AB7P2AB8P2ABCP2B81P2B93P0299

References: gsi.ext.gm.com, gsi.ext.gm.com, fordservicecontent.com, static.nhtsa.gov.