OBD-II code · Network (extended)
U3548 High Voltage System Interlock Circuit P High
HVIL loop P voltage above expected range. 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.
Is it safe to drive with U3548?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyInterlock loop open
- Less likelyGateway module routing CAN messages incorrectly
- Less likelyCAN 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
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 P, Hvil Wiring
Related codes
- U3518High Voltage System Interlock Circuit C High
- U351CHigh Voltage System Interlock Circuit D High
- U3520High Voltage System Interlock Circuit E High
- U3524High Voltage System Interlock Circuit F High
- U3528High Voltage System Interlock Circuit G High
- U352CHigh Voltage System Interlock Circuit H High
- U3530High Voltage System Interlock Circuit J High
- U3534High Voltage System Interlock Circuit K High
- U3538High Voltage System Interlock Circuit L High
- U353CHigh Voltage System Interlock Circuit M High
- U3540High Voltage System Interlock Circuit N High
- U3544High Voltage System Interlock Circuit O High
- U3545High Voltage System Interlock Circuit P
- U3546High Voltage System Interlock Circuit P Performance
- U3547High Voltage System Interlock Circuit P Low
- U3549Hydrogen Tank High Pressure Sensor 1 Circuit
- U354AHydrogen Tank A Temperature Sensor 1 Circuit
- U354BHydrogen Tank A Temperature Sensor 2 Circuit
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.