What it means
The control module monitors the operation and reported status of high-voltage power outlet control module B on DC/AC converter A. It sets this code when module B reports a fault or its operation fails the system’s checks.
At a glance
- Usually lights the airbag (SRS) or body-system warning light
How it works
DC/AC converter A distributes AC power through its high-voltage outlets, and control module B reports or manages its outlet function. B012D is specific to module B: it sets when module B reports a fault or fails the system’s operating checks, which can result from the module itself or its supply, wiring, or communication link.
Common causes
Most likely first.
- Internal failure of outlet control module B
- Open or shorted module wiring
- Loose or corroded connector
- Power or ground supply fault
- Communication fault with the module
Symptoms
- Warning light or symbol related to the affected system
- Comfort or safety function impaired
How to diagnose it
- Record freeze-frame data and scan for related converter and network codes to determine whether the fault is limited to module B.
- Inspect module B’s harness and connector for damage, moisture, corrosion, loose fit, or displaced pins.
- Test module B’s power and ground circuits against the wiring diagram and manufacturer’s specification.
- Check the communication wiring and terminals for module B for open circuits, shorts, and poor connections.
- If the circuits and network connection pass, follow the manufacturer’s diagnostic procedure to verify a module B internal fault.
Common fixes
- Reseat or clean the module B connector and repair damaged terminals.
- Repair open or shorted wiring serving module B.
- Correct a power or ground supply fault to module B.
- Repair a communication fault affecting module B.
- Replace outlet control module B if testing confirms its internal failure.
Can I keep driving?
Do not depend on the outlet function controlled by module B until it is repaired. Driving may remain possible if no other system warnings are present, but avoid handling high-voltage components.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.