What it means
The control module monitors the electrical circuit for switch B in DC/AC converter control module A. It sets this code when the circuit has an electrical fault, such as an open, short, or abnormal signal.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
DC/AC converter control module A monitors the electrical circuit for its switch B. P2DAA sets when that circuit has an electrical fault, such as an open, short, or abnormal signal, and the converter may reduce or disable its function.
Common causes
Most likely first.
- Internal switch failed
- Wiring fault
Symptoms
- Check-engine or hybrid-system warning light
- Reduced or unavailable DC/AC converter function
How to diagnose it
- Record freeze-frame data and use a scan tool to check switch B status and DC/AC converter faults in module A.
- Inspect the switch B circuit wiring and connectors at converter control module A for chafing, damage, corrosion, or loose terminals, observing manufacturer high-voltage safety procedures.
- Use the wiring diagram to check switch B circuit continuity and for shorts to power or ground with the vehicle safely isolated as specified by the manufacturer.
- Check circuit supply and ground conditions and compare measurements with the manufacturer’s specification.
- If the wiring and connections test correctly, follow the manufacturer’s procedure to test switch B and converter control module A internally.
Common fixes
- Repair damaged or chafed wiring in the switch B circuit.
- Clean or repair loose or corroded terminals at converter control module A.
- Correct a circuit open or short identified during testing.
- Replace the failed switch B or converter control module A if circuit tests pass and internal testing confirms the fault.
Can I keep driving?
Because this fault can reduce converter function and may trigger limp mode, avoid relying on affected electrical or hybrid functions and stop if the vehicle’s warnings indicate an unsafe condition. Have high-voltage system checks performed only by someone equipped to follow the manufacturer’s safety procedure.
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.