OBD-II code · Network (extended)
U3549 Hydrogen Tank High Pressure Sensor 1 Circuit
Generic electrical fault on the high-pressure hydrogen tank pressure sensor 1 (typical operating range up to 700 bar on FCEVs).
Is it safe to drive with U3549?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyPressure sensor failed
- 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
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- H2 Tank Pressure Sensor 1, Sensor Wiring
Related codes
- U3546High Voltage System Interlock Circuit P Performance
- U3547High Voltage System Interlock Circuit P Low
- U3548High Voltage System Interlock Circuit P High
- U354AHydrogen Tank A Temperature Sensor 1 Circuit
- U354BHydrogen Tank A Temperature Sensor 2 Circuit
- U354CHydrogen Tank B Temperature Sensor 1 Circuit
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.