P0A09: DC/DC Converter Status Circuit Low
2 vehicles · 2 makes
Most Reported On
P0A09 is an OBD-II diagnostic trouble code meaning “DC/DC Converter Status Circuit Low.” This code is found on hybrid and electric vehicles and indicates a low status signal from the DC/DC converter, the device that steps the high-voltage battery's power down to the 12-volt level needed to run lights, accessories, and charge the 12V battery. The converter reports its operating status to the vehicle's computer, and a low signal means it isn't operating or communicating as expected. Because the 12V system depends on this converter, problems can lead to a dead 12V battery, stalling, or no-start conditions. Causes typically include the converter itself, its wiring and connectors, or low system voltage. This code is most commonly reported on 2024-2026 GMC Hummer EV SUV, and 2024-2025 Chevrolet Silverado EV.
Common Causes
Diagnostic Tools
To diagnose P0A09, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
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- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
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- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
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- AutoVIN for vehicle identification
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Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
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- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
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FAQ
What does P0A09 mean?
P0A09 stands for "DC/DC Converter Status Circuit Low." This code is found on hybrid and electric vehicles and indicates a low status signal from the DC/DC converter, the device that steps the high-voltage battery's power down to the 12-volt level needed to run lights, accessories, and charge the 12V battery. The converter reports its operating status to the vehicle's computer, and a low signal means it isn't operating or communicating as expected. Because the 12V system depends on this converter, problems can lead to a dead 12V battery, stalling, or no-start conditions. Causes typically include the converter itself, its wiring and connectors, or low system voltage.
What are the most common causes of P0A09?
The most common causes of P0A09 are: Faulty DC/DC converter (often integrated in the inverter assembly), Open or shorted wiring in the DC/DC converter circuit, Poor electrical connection or corroded connector, Weak or failing 12V auxiliary battery, Converter over/under-voltage or overheating fault, CAN/communication fault to the converter, Faulty PCM/hybrid control module (rare). The specific cause varies by vehicle.
How much does it cost to fix P0A09?
Repair costs vary widely depending on the root cause and vehicle.
Which vehicles are affected by P0A09?
Au7o has documented P0A09 across 2 vehicle models from 2 manufacturers: Chevrolet, GMC.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.