What it means
The hybrid system detects loss of high-voltage interlock continuity. The interlock loop is a safety feature that disables HV power if any service connector is opened.
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 is a safety loop that passes through access points such as the service connector and high-voltage cable connections. The hybrid control module checks for a continuous loop and sets P0A0A when it detects that continuity has been lost, which can prevent high-voltage power from being enabled.
Common causes
Most likely first.
- Service connector loose or damaged
- HV cable damaged
Symptoms
- Hybrid system warning light on
- Vehicle may not enter READY mode
- Possible reduced or unavailable hybrid power
How to diagnose it
- Read freeze-frame data and hybrid control module codes to see when the interlock fault occurred and whether related high-voltage faults are present.
- Check the service connector is fully seated and its housing and latch are undamaged, following the vehicle's specified high-voltage safety procedure.
- Visually inspect accessible high-voltage cable routing and connectors for impact damage, abrasion, or a loose connection without opening or probing the high-voltage system.
- Use the scan tool's interlock status data, if available, to identify whether the loop is currently open and whether the status changes after the service connector is correctly secured.
- Have the interlock loop and its wiring checked with the manufacturer's specified safe isolation and test procedure to locate the interruption.
Common fixes
- Reseat a loose service connector using the manufacturer's procedure.
- Repair or replace a damaged service connector or latch.
- Repair or replace damaged high-voltage cable or interlock wiring using the specified parts and safety procedure.
Can I keep driving?
If the vehicle will not enter READY or hybrid power is reduced, do not rely on it for a trip; arrange safe recovery if needed. Do not handle high-voltage connectors or cables, since the system can cause serious injury.
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.