P0A94 on BMW
DC/DC Converter Performance
P0A94 on BMW vehicles indicates dc/dc converter performance. Au7o has documented this code across 1 BMW model — most commonly on iX. This hybrid/electric vehicle code sets when the hybrid control system detects that the DC/DC converter is not performing within expected parameters. The DC/DC converter steps the high-voltage battery power down to the 12-volt level that runs the car's lights, accessories, and control modules, so a performance fault can affect the whole low-voltage system. Symptoms may include warning lights, reduced power, the hybrid system not starting, or a discharged 12-volt battery. Because high-voltage components are involved, diagnosis and repair should be done by a qualified hybrid technician.
Common Causes of P0A94
- •Faulty inverter/converter assembly (DC/DC converter)
- •Open or shorted wiring in the converter circuit
- •Poor electrical connection at the converter
- •Weak or failing 12-volt battery
- •High-voltage system or cooling fault affecting the converter
- •Software/control module calibration issue
- •Faulty hybrid control module (less common)
P0A94 on BMW by Model
BMW iX(1 issue)
- Combined Charging Unit Assembly Defect Causes Power Interruption While Driving - Recall 23V-4492022-2023
NHTSA campaign 23V449000 recalls BMW iX, i4 and i7 vehicles whose Combined Charging Unit was not manufactured correctly, leaving internal components improperly connected or assembled. The important distinction for iX owners is the failure mode: this campaign is not about AC charging refusing to work, it is about the CCU interrupting electrical power while the vehicle is in motion. NHTSA records the consequence as an improperly assembled CCU that 'can interrupt power and cause engine stall, increasing the risk of a crash.' On the iX the CCU is the combined on-board charger and DC/DC converter, so a fault there simultaneously threatens both traction power and the 12V supply that runs steering assist, brake assist and lighting. This is consistent with the 2023 iX complaint file, which contains multiple reports of losing propulsion and, in the worst cases, of losing power-assisted steering and braking together at speed - one complainant describing that they 'lost power assisted steering AND power assisted braking. I had to decelerate with no power brakes.' The remedy is replacement of the CCU, not a software update.
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View P0A94 across all makes →Frequently Asked Questions
What does P0A94 mean on BMW?▼
P0A94 stands for "DC/DC Converter Performance." This hybrid/electric vehicle code sets when the hybrid control system detects that the DC/DC converter is not performing within expected parameters. The DC/DC converter steps the high-voltage battery power down to the 12-volt level that runs the car's lights, accessories, and control modules, so a performance fault can affect the whole low-voltage system. Symptoms may include warning lights, reduced power, the hybrid system not starting, or a discharged 12-volt battery. Because high-voltage components are involved, diagnosis and repair should be done by a qualified hybrid technician. On BMW specifically, this code is documented across 1 model.
What causes P0A94 on BMW vehicles?▼
Common causes on BMW: Faulty inverter/converter assembly (DC/DC converter), Open or shorted wiring in the converter circuit, Poor electrical connection at the converter, Weak or failing 12-volt battery, High-voltage system or cooling fault affecting the converter. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0A94 on a BMW?▼
Repair costs vary widely depending on the root cause and specific BMW model.
Which BMW models have P0A94 documented?▼
Au7o has documented P0A94 on 1 BMW model: iX.