Powertrain, generic (extended)

P2393 Diesel Intake Air Flow B Control Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P2393 is the counterpart of P2392: one of the B-throttle motor leads has contact with battery voltage, for example through a pinched harness or a bridged pin in the connector, so the output stage sees an overcurrent as soon as it switches. No manufacturer publishes P2393. For the A valve GM's 2017 diesels flag the analogous P02E3 when more than 9 A flows through the H-bridge in 160 of 200 checks and store it on the second trip. Ford's 2023 diesels need just 0.2 s to recognise the A-valve short. The ECM then disables the driver to protect itself. If P239B is stored as well, a shorted motor winding is a likelier culprit than the harness. Apart from the MIL the driver usually notices nothing; emissions and regeneration suffer.

Likely causes

Motor lead pinched against a live wire or terminal
Bridged pins in the connector (moisture, corrosion)
Shorted turns in the throttle motor
Faulty output stage in the engine control module

Symptoms

  • MIL on
  • Filter regeneration not carried out
  • Possibly blown fuse or further circuit codes on the same supply

Repair estimate

DifficultyMediumDIY possible
Parts and labour€40–500
Time0.5–2 h

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

Parts involved

diesel intake throttle valvethrottle valve motoractuator wiring

Related codes

P2392P2390P239BP02E3

References: law.cornell.edu, gsi.ext.gm.com, fordservicecontent.com.