What it means
Generic fault on HVIL loop G. 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 G checks the connection state of monitored components and connectors in that section of the high-voltage system. This generic code indicates an electrical fault on loop G without identifying a high, low, or performance condition; a connector that is not fully mated is a possible cause.
Common causes
Most likely first.
- HV connector not fully mated
- 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 related interlock or communication codes before clearing the fault.
- With the vehicle powered down according to manufacturer instructions, inspect accessible loop G connectors and wiring for incomplete seating, corrosion, or physical damage.
- Compare live status for loop G with the other interlock loops, if supported, to determine whether the fault is specific to G.
- Have a qualified high-voltage technician inspect and test loop G and its connectors using the manufacturer's safety procedures and specifications.
- If loop G passes, check gateway message routing and CAN termination against vehicle wiring information and manufacturer specifications.
Common fixes
- Fully seat a loose loop G connector using the manufacturer's procedure.
- Repair damaged or corroded loop G wiring or terminals.
- Replace a loop G interlock component confirmed to be faulty.
- Correct verified gateway routing or CAN termination faults.
Can I keep driving?
If high-voltage warnings, reduced power, or shutdown behavior are present, avoid driving because the vehicle may limit or disable propulsion or charging. Have it checked by a qualified high-voltage technician.
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.