P0A94: DC/DC Converter A Performance

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.

Symptoms

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

Most likely causes

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

What to check, in order

Start with the simplest. You can tick off each step.

1. Read the codes with a hybrid-compatible scanner and write down the freeze frame data
2. Compare the reading with other engine data while varying the engine speed.
3. Make sure the battery cooling air intake is clean
4. Check the 12 V auxiliary battery, which can also trigger warnings
5. Leave any high-voltage measurements to a specialized repair shop

Good to know

• It can trigger limp mode.
• It affects emissions.

What each character of P0A94 means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• A: Hybrid or air and fuel
• 94: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0A94?

If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.

What causes code P0A94?

The most common causes are: damaged power transistors in the boost converter / inverter assembly; thermal stress from insufficient inverter cooling; outstanding recall or software update not performed.

Related codes

• P0A1AGenerator Control Module
• P0A93Inverter A Cooling System Performance
• P0A78Drive Motor A Inverter Performance

Sources

• static.nhtsa.gov: MC 10187254 9999
• static.nhtsa.gov: RCRIT 14V053 7795
• static.nhtsa.gov: RCRIT 18V684 3117
• static.nhtsa.gov: MC 10182972 9999

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.