OBD-II Code

P0A94

Severity

Not yet reviewed

Nobody on our side has assessed this code yet, so we are not going to guess at how serious it is.

Can you drive it

We cannot say

Treat it as unknown until a shop reads it with live data. If the check-engine light is FLASHING, stop driving as soon as it is safe to — that means an active misfire, whatever the code.

Indicative cost (USD)

$680–$3,200

From this code's diagnostic notes. Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.

P0A94 is set when the DC/DC converter — the component that steps the high-voltage hybrid pack (200-650V depending on platform) down to 12-14V to charge the auxiliary battery and run accessories — is not performing to spec; the BECM monitors output voltage against commanded setpoint and trips P0A94 when the delta exceeds 0.5V for more than 5 seconds, when output current is below demand, or when internal temperature exceeds 110C.

How a shop works this

Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.

Note every code that is set, not just this one.
Codes that appear together usually narrow the cause faster than any one of them read alone.
Read the freeze frame — the conditions the fault was recorded under.
Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.
Confirm the fault is current rather than history.
Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.
Then follow the diagnostic notes further down this page, in the order they are written.
They are written in the order a shop works this code, cheapest checks first. Where they name a component, inspect its wiring and connector before replacing it.

If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.

Common symptoms

Check engine light

Read the full diagnostic procedureP0A94 is set when the DC/DC converter — the component that steps the high-voltage hybrid pack (200-650V depending on platform) down to 12-14V to char…+

Cheapest-first diagnostic ladder

measure the 12V auxiliary battery voltage with the hybrid system READY — a healthy DC/DC converter holds the aux battery at 13.8-14.4V, and anything below 13.2V with hybrid READY confirms the converter is not contributing.
Verify the aux battery itself is not the failure.
Caveat: P0A94 will set within minutes of jump-starting a hybrid from another vehicle if the donor's alternator spikes the aux battery above 15.5V — it can damage the DC/DC converter's output stage, and Toyota specifically warns against jump-starting Prius FROM another car.

Vehicle-specific patterns2010-2015 Toyota Prius Gen 3 (ZVW30) — DC/DC converter integrated into inverter assembly, failure usually thermal from inverter coolant pump death (P…+

2010-2015Toyota Prius Gen 3 (ZVW30) — DC/DC converter integrated into inverter assembly, failure usually thermal from inverter coolant pump death (P0A93 + P0A94 paired); inverter assembly replacement P/N G9200-47241.
2011-2015Chevrolet Volt — APM (Accessory Power Module) failure throws P0A94 with reduced propulsion; GM TSB PIE0398 covers APM replacement under extended warranty 8yr/100K.
2008-2013Chevrolet Tahoe Hybrid / Silverado Hybrid 2-mode — APM failure on 2-mode platform.
2005-2012Ford Escape Hybrid — DC/DC converter is a separate unit under the hood.

Estimated repair$680 to $3,200.

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