Internal failure of the DC-to-AC converter module, such as a shorted switching transistor or failed capacitor, causing the output voltage to spike.; A short circuit or damaged insulation in the wiring between the converter and the power outlet 'B', allowing the high-voltage output to feed back into the module.; A faulty power outlet 'B' receptacle with internal contacts shorted or contaminated by debris or liquid.; Corroded or loose ground connections for the converter module, causing voltage regulation to drift high.; A malfunctioning power outlet control module 'B' that misreads the converter output voltage and sets a false high-voltage code.; Water intrusion into the converter module or outlet assembly, leading to electrical leakage and voltage spikes.; A failed voltage feedback sensor inside the converter module, reporting an incorrect high voltage to the control module.

DTC codes / B01xx · Airbags, seats, doors, lights and comfort systems / B012D

B012DDC/AC Converter A High Voltage Power Outlet Control Module "B"

B012D indicates that the body control module (BCM) or dedicated power outlet control module has detected an abnormally high voltage on the output of the DC-to-AC (direct current to alternating current) converter that feeds power outlet 'B'. The module monitors the converter's high-voltage bus and sets this code when the measured voltage exceeds the calibrated threshold, typically due to a fault inside the converter, a shorted outlet, or a wiring problem.

SystemBody

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaAirbags, seats, doors, lights and comfort systems

Symptoms you may notice

The 110-volt or 220-volt AC power outlet labeled 'B' stops working or delivers no power to connected devices.
The outlet may work intermittently, cutting out under load or after a short period of use.
A warning light or message on the dashboard indicates a power outlet fault or a charging system issue.
Connected devices may charge slowly, run erratically, or fail to power on at all.
In some vehicles, the infotainment screen displays a specific message about the AC outlet being unavailable.
Often no symptoms besides the warning light, especially if the outlet is rarely used.

Common causes, most likely first

Internal failure of the DC-to-AC converter module, such as a shorted switching transistor or failed capacitor, causing the output voltage to spike.
A short circuit or damaged insulation in the wiring between the converter and the power outlet 'B', allowing the high-voltage output to feed back into the module.
A faulty power outlet 'B' receptacle with internal contacts shorted or contaminated by debris or liquid.
Corroded or loose ground connections for the converter module, causing voltage regulation to drift high.
A malfunctioning power outlet control module 'B' that misreads the converter output voltage and sets a false high-voltage code.
Water intrusion into the converter module or outlet assembly, leading to electrical leakage and voltage spikes.
A failed voltage feedback sensor inside the converter module, reporting an incorrect high voltage to the control module.

How to diagnose and fix it

Inspect the power outlet 'B' receptacle and its wiring for visible damage, corrosion, or debris, and clean or replace the outlet if necessary.
Check the converter module's ground connections and the outlet's ground circuit for looseness or corrosion, and tighten or repair as needed.
Measure the AC voltage at the outlet with a multimeter while a small load is connected; if it exceeds the specified range, the converter is likely faulty.
Disconnect the converter module and inspect the harness connectors for bent pins, water intrusion, or chafed wires, repairing any damage found.
Substitute a known-good converter module or power outlet control module 'B' to see if the code clears and the outlet functions correctly.
Use a scan tool to monitor the converter's voltage feedback parameter in real time and compare it with a direct measurement at the outlet to identify a sensor or module reporting error.
If all wiring and connections are good and the code persists, replace the DC-to-AC converter module and verify the repair by clearing the code and testing the outlet under load.

What a high-voltage outlet code really means

A high-voltage code on a DC-to-AC converter often results from a failing converter under load, not from a wiring short, so load-testing the outlet is more revealing than a simple voltage check.
Some vehicles set B012D when the converter's cooling fan fails, causing the module to overheat and momentarily spike its output voltage; the fan is frequently overlooked.
The code can be set by a weak or failing 12-volt vehicle battery, because low input voltage forces the converter to work harder and can produce unstable output.
A power outlet that has been used with a device drawing more than its rated current can damage the converter's internal protection circuit and trigger this code without any external wiring fault.
Technicians sometimes replace the converter only to find the code returns because the outlet 'B' receptacle has a hairline crack that shorts only when a plug is inserted.

Can I keep driving with B012D?

The vehicle remains safe to drive because the high-voltage outlet is an accessory circuit, but avoid using outlet 'B' until the fault is repaired to prevent damage to connected devices or further converter failure. If the warning light is accompanied by a charging system message, have the vehicle inspected promptly.

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.