What P0A94 means
P0A94 reports that a DC/DC converter in the high-voltage system does not perform as commanded.
How the engine computer detects it
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.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- MIL, hybrid system and other warning lamps
- Fail-safe mode with greatly reduced power
- Vehicle may stop and not restart
Common causes
- Damaged power transistors in the boost converter / inverter assembly Most likely
- Thermal stress from insufficient inverter cooling Possible
- Outstanding recall or software update not performed Possible
How to diagnose P0A94
- Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
- Inspect the parts involved: dcdc converter.
- Work through the causes above from most to least likely, cheapest checks first.
- Clear the code and drive a full drive cycle to confirm the repair held.
Vehicles that report P0A94 most
| Vehicle | Years | Reports | Share | Median miles |
|---|---|---|---|---|
| Toyota Prius | 2010–2014 | 5 | — | |
| Toyota Prius C | 2012–2014 | 5 | — |
Counts of owner complaints to the NHTSA that mention P0A94 (12 in total), not failure rates: popular models get more complaints simply because more of them are on the road. Models with fewer than 3 complaints are left out.
Reading the code
- P
- Powertrain
- 0
- Generic (SAE) code
- A
- Hybrid and electric propulsion
- 94
- Specific fault
Questions drivers ask
Can I drive with code P0A94?
Drive gently and only as far as you need to. The engine computer may limit power to protect the engine, so avoid highways and heavy traffic until it's fixed. If the check engine light starts flashing, pull over.
Will my car pass an emissions inspection with P0A94?
Probably not in states that test vehicles with an OBD-II scan: an emissions-related code that keeps the check engine light on is usually an automatic fail. Rules differ by state and county, so check yours.
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.