What it means
HVIL loop K timing/pattern does not match expected behavior. A communication loss with this module breaks any function relying on its data — diagnostic tools may show 'no response' and dependent modules can fall into limp mode.
At a glance
- Usually lights the warning light of the system that lost communication
- The engine or gearbox may go into limp mode
How it works
The high-voltage interlock loop (HVIL) K lets the control module monitor continuity through part of the high-voltage system. This performance code sets when the timing or pattern of the loop K signal does not match the expected behavior, suggesting an irregular or intermittent response.
Common causes
Most likely first.
- Intermittent contact in HV connector
- Gateway module routing CAN messages incorrectly
- CAN terminating resistor (120 Ω) drifted out of spec
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
How to diagnose it
- Save freeze-frame data and scan all modules for loop K, gateway, and CAN faults to see whether the event coincided with other network symptoms.
- Watch live data for the HVIL K status while the code is current and note any dropouts or unexpected changes.
- With the high-voltage system made safe according to the manufacturer's procedure, inspect accessible loop K wiring and connectors for looseness, corrosion, or damage that could cause intermittent contact.
- Have a qualified technician test loop K continuity and signal behavior using the manufacturer's procedure, checking whether the reading changes at connectors or harness sections.
- If loop K tests consistently, verify gateway routing and CAN termination against the manufacturer's specifications.
Common fixes
- Reseat a loose loop K connector following the manufacturer's high-voltage safety procedure.
- Repair intermittent loop K wiring or connector contact.
- Correct a confirmed gateway routing or configuration fault.
- Repair CAN termination if it is outside the manufacturer's specification.
Can I keep driving?
An intermittent loop K signal may cause high-voltage functions to shut down unexpectedly or trigger limp mode. Avoid long trips and stop safely if power drops or warnings appear; have a qualified technician diagnose the fault.
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.