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DTC codes / P0Dxx · Hybrid propulsion / P0D16

P0D16Battery Charging System A High Voltage Interlock Circuit Performance

P0D16 indicates that the battery charging system's high-voltage interlock loop has reported a performance fault, meaning the safety circuit that confirms all high-voltage connectors are properly seated is not behaving as expected. The computer monitors the interlock circuit for continuity and signal integrity, and it has detected a condition outside the normal operating range, which can prevent the high-voltage system from energizing or charging.

SystemPowertrain
Code typeGeneric (all makes)
SeverityHigh
Fix difficultyProfessional
AreaHybrid propulsion

Symptoms you may notice

  • Illumination of the high-voltage system warning light or service vehicle soon message
  • The vehicle may refuse to start or enter ready-to-drive mode
  • Charging may be disabled or interrupted, leaving the high-voltage battery depleted
  • A message indicating a high-voltage interlock fault or safety system error
  • Often no symptoms besides the warning light, with the vehicle operating normally

Common causes, most likely first

  1. A high-voltage connector that is not fully latched or has a damaged interlock pin
  2. Corrosion or water intrusion in a high-voltage interlock connector
  3. A broken or chafed interlock wire in the harness
  4. A faulty high-voltage component with an internal interlock switch, such as the battery pack, inverter, or charger
  5. A malfunctioning battery energy control module or interlock detection circuit
  6. Aftermarket accessories or improper previous repairs disturbing the high-voltage wiring

How to diagnose and fix it

  1. Inspect all high-voltage connectors for proper seating, latch engagement, and signs of corrosion or damage
  2. Check the interlock circuit wiring for continuity and shorts using a multimeter, following the manufacturer's service information
  3. Verify the interlock signal at the battery energy control module and compare to specifications
  4. Test individual high-voltage components' interlock switches if accessible, disconnecting the high-voltage battery service plug first
  5. Repair or replace any damaged connector, terminal, or wire section in the interlock circuit
  6. Clear the diagnostic trouble codes and perform a road test to confirm the fault does not return

Interlock faults that mimic component failures

  • A partially latched high-voltage connector is the most common cause of this code, and it often happens after service work that required disconnecting the high-voltage system.
  • The interlock circuit is a low-voltage loop, so a code P0D16 does not necessarily mean the high-voltage battery or motor is defective; the fault is usually in the wiring or connector.
  • Some vehicles set this code when the 12-volt battery is weak or has been disconnected, because the module loses its interlock reference during low-voltage conditions.
  • Aftermarket alarm or remote start installations that tap into wiring near high-voltage components can disturb the interlock circuit and trigger this code.
  • Always follow the manufacturer's high-voltage disconnect procedure before probing interlock circuits, as the system can retain dangerous voltage even with the key off.

Can I keep driving with P0D16?

Do not continue driving if the vehicle will not enter ready mode or shows a high-voltage safety warning, as the high-voltage system may be disabled and the vehicle could lose power unexpectedly. If the only symptom is the warning light and the vehicle drives normally, limit driving to a short distance to a qualified repair facility and avoid charging until diagnosed.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

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

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