OBD-II code · Network (extended)
U3511 High Voltage System Interlock Circuit B
Generic fault on the second high-voltage interlock loop (HVIL) circuit. The interlock detects whether HV connectors are properly mated; an open loop forces the HV system into a safe state.
Is it safe to drive with U3511?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyHV connector not fully mated
- PossibleInterlock pilot pin damaged
- Less likelyGateway module routing CAN messages incorrectly
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
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–5 h
- Emissions test
- Usually unaffected
- Parts involved
- Hvil Loop B, Hv Connectors
Related codes
- U3515High Voltage System Interlock Circuit C
- U3519High Voltage System Interlock Circuit D
- U351DHigh Voltage System Interlock Circuit E
- U3521High Voltage System Interlock Circuit F
- U3525High Voltage System Interlock Circuit G
- U3529High Voltage System Interlock Circuit H
- U352DHigh Voltage System Interlock Circuit J
- U3531High Voltage System Interlock Circuit K
- U3535High Voltage System Interlock Circuit L
- U3539High Voltage System Interlock Circuit M
- U353DHigh Voltage System Interlock Circuit N
- U3541High Voltage System Interlock Circuit O
- U350EControl Module Cooling Fan Circuit High
- U350FControl Module Cooling Fan Circuit Range/Performance
- U3510Control Module Missing Calibration
- U3512High Voltage System Interlock Circuit B Performance
- U3513High Voltage System Interlock Circuit B Low
- U3514High Voltage System Interlock Circuit B High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.