Powertrain, generic · Hybrid propulsion

P0A94 DC/DC Converter A Performance

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0A94 reports that a DC/DC converter in the high-voltage system does not perform as commanded. In Toyota hybrids this is the boost converter inside the inverter assembly, which raises the battery voltage before it reaches the motor inverters. Toyota documents P0A94 for 2010–2015 Prius and 2012–2017 Prius v together with P0A1A, P324E and P3004 (bulletin T-SB-0003-21): the cause is damage in the inverter with converter, and the repair depends on the detail code. Recalls 14V-053 and 18V-684 address transistors in the intelligent power module that could overheat; the car then enters a fail-safe mode with reduced power. Not to be confused with the 14 V power module codes P0A86 to P0A8F.

Likely causes

Damaged power transistors in the boost converter / inverter assembly
Thermal stress from insufficient inverter cooling
Outstanding recall or software update not performed

Symptoms

  • MIL, hybrid system and other warning lamps
  • Fail-safe mode with greatly reduced power
  • Vehicle may stop and not restart

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€300–4,000
Time1–6 h

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

Parts involved

dcdc converter

Related codes

P0A1AP0A93P0A78

References: static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov.