Open circuit in the wiring between the DC/AC converter and the outlet, such as a broken wire or loose connector; Faulty DC/AC converter (inverter) internal failure causing an open circuit or high voltage; Poor ground connection for the converter or outlet circuit; Damaged outlet receptacle or internal contacts; Corrosion or water intrusion in the outlet or connector; BCM software glitch or internal fault misreporting the circuit condition

DTC codes / B01xx · Airbags, seats, doors, lights and comfort systems / B0127

B0127DC/AC Converter A High Voltage Power Outlet "A" Circuit/Open

B0127 indicates that the body control module (BCM) has detected an open circuit or high voltage condition on the DC/AC converter's high-voltage power outlet 'A' circuit. In plain English, the vehicle's computer sees a problem with the power supply to the high-voltage AC outlet, often caused by a break in the wiring or a faulty converter.

SystemBody

Code typeGeneric (all makes)

SeverityLow

Fix difficultyIntermediate

AreaAirbags, seats, doors, lights and comfort systems

Symptoms you may notice

The high-voltage power outlet (AC outlet) does not provide power to devices
A warning light or message on the dashboard indicating an outlet fault
The outlet may work intermittently or only when the vehicle is in certain states
Often no symptoms besides the warning light, as the outlet may not be used regularly
Other electrical accessories on the same circuit may also fail if the open circuit affects shared wiring

Common causes, most likely first

Open circuit in the wiring between the DC/AC converter and the outlet, such as a broken wire or loose connector
Faulty DC/AC converter (inverter) internal failure causing an open circuit or high voltage
Poor ground connection for the converter or outlet circuit
Damaged outlet receptacle or internal contacts
Corrosion or water intrusion in the outlet or connector
BCM software glitch or internal fault misreporting the circuit condition

How to diagnose and fix it

Inspect the outlet and converter connectors for loose pins, corrosion, or damage; clean and reseat as needed
Check the wiring harness for continuity between the converter and outlet using a multimeter, looking for opens or shorts
Test the converter's output voltage and ground circuit; compare to manufacturer specifications
Check for any related technical service bulletins (TSBs) or software updates for the BCM
If wiring and connectors are good, test the converter with a known-good unit or follow diagnostic flow to confirm failure
Replace the faulty converter or repair the open circuit as needed, then clear codes and verify operation

Before you replace the DC/AC converter

A common oversight is assuming the converter is bad when the real issue is a loose or corroded connector at the outlet, which is often easier and cheaper to fix.
The code can set intermittently due to vibration or temperature changes affecting a marginal connection, so a wiggle test of the harness while monitoring live data can be revealing.
Some vehicles require the high-voltage system to be enabled or the engine running for the outlet to work, so testing with the vehicle off may give false results.
The BCM may set this code if the outlet is used with a device that draws too much current, causing a voltage drop that mimics an open circuit; always check for aftermarket accessories.
Related codes in the B0xxx range may also be present if the fault affects shared power or ground circuits, so a full system scan is essential before parts replacement.

Can I keep driving with B0127?

The vehicle remains safe to drive because the high-voltage outlet is an accessory and does not affect engine or safety systems. Avoid using the outlet until the fault is repaired, and do not attempt to bypass or modify the circuit.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.