What it means
The high-voltage interlock circuit for battery charging system A does not meet expected performance criteria. The code alone does not identify the cause.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The high-voltage interlock circuit for battery charging system A forms a monitored safety loop, and the module checks how its signal behaves. P0D16 sets when the signal fails the expected performance criteria, such as an inconsistent or high-resistance connection, without identifying the exact point of failure by itself.
Common causes
Most likely first.
- Interlock signal drifted
- High-resistance contact
Symptoms
- Charging system warning light may come on
- Charging may be interrupted or unavailable
- Vehicle may limit high-voltage operation
How to diagnose it
- Save freeze-frame data and related codes to see whether the performance fault occurred during charging or another high-voltage operating state.
- Review live interlock status for battery charging system A and note whether it fluctuates as the fault appears.
- Inspect accessible interlock connectors and wiring for looseness, corrosion, or damage without opening high-voltage enclosures.
- Have loop continuity and voltage drop checked under the manufacturer's procedure to find a high-resistance contact.
- If the loop tests correctly, check the module's interlock input and related connector for an intermittent monitoring fault.
Common fixes
- Secure a loose accessible interlock connector as directed by the manufacturer's procedure.
- Clean or replace corroded interlock terminals causing high resistance.
- Repair damaged interlock wiring or replace the faulty loop component identified by testing.
- Repair a module input fault only after the interlock loop passes its checks.
Can I keep driving?
The charging system may interrupt charging or limit high-voltage operation, so do not depend on it for a charge-dependent trip while the warning is active. Keep clear of high-voltage components and have a recurring fault diagnosed promptly.
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.