Powertrain, generic (extended)

P2D23 Turbocharger Interstage Pressure Sensor A Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2D23 says the interstage pressure signal sits below the lowest voltage a working sensor can produce. Typical causes are a signal wire shorted to ground, a lost 5 V supply or an internal sensor short. No public table gives a threshold for this sensor; for comparison, Ford's 2023 diesels treat a DEF pressure sensor below 0.2 V as circuit low. The sensor itself sits between the two compressors of a series turbo system, as GM's two-stage control patent describes, where its value guides the low-pressure stage. California requires out-of-range checks on every such input. With the value missing, the controller usually falls back to a model and caps boost. A high reading is P2D24.

Likely causes

Signal wire shorted to ground
5 V reference open or pulled down by another sensor
Sensor shorted internally

Symptoms

  • Check engine light
  • Boost limited, noticeably less power
  • Further codes if the shared sensor supply is affected

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–600
Time0.5–2.5 h

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

Parts involved

turbo interstage pressure sensor awiring harnessecm

Related codes

P2D24P2D21P2D22P2D25P0241

References: patents.google.com, fordservicecontent.com, law.cornell.edu.