Powertrain, generic (extended)

P2DA9 DC/AC Converter Control Module A Switch A Circuit Range/Performance

Check engine lightUsually off
EmissionsNot relevant
Drive cycleRequired
Limp modeNo

P2DA9 belongs to switch A of the DC/AC converter control module A, the inverter that supplies AC sockets in the vehicle. Unlike P2DA8 the circuit is intact, but the switch does not behave as expected: its signal sits between valid states, or the commanded state does not show up at the output. CARB 13 CCR 1968.2 describes this type of check as a rationality or functional test kept apart from circuit faults. Ford's patent US11043801B2 gives a practical example: the controller compares voltage ahead of and behind each socket switch and reports a switch error when voltage arrives upstream but not downstream. No manufacturer documents P2DA9 publicly. Worn or sticking contacts, a relay that does not pull in, contact resistance or a jammed button are typical; outlets then work only intermittently.

Likely causes

Worn, sticking or burnt contacts of switch A or its relay
High contact resistance in connector or outlet wiring
Outlet button jammed by dirt or damage
Voltage sensing in the converter module implausible

Symptoms

  • Outlets of group A work only intermittently
  • Outlet power switches off unexpectedly under load
  • Switch position in the display does not match the outlet state

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–1,500
Time0.5–3 h

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

Parts involved

dcac converter module a switch awiring harnessdc ac converter module a

Related codes

P2DA8P2DABP0364U0589

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