OBD-II code · Network (extended)
U355D Expander Inlet Pressure Sensor 1 Circuit
Generic fault on the inlet pressure sensor 1 of the expander (turbine recovering energy from the cathode exhaust on FCEVs).
Is it safe to drive with U355D?
Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.
Common causes
- Most likelySensor 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
- 1–4 h
- Emissions test
- Usually unaffected
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Expander Inlet Pressure Sensor 1, Sensor Wiring
Related codes
- U355EExpander Inlet Pressure Sensor 2 Circuit
- U355ACharge Air Cooler Outlet Pressure Sensor 1 Circuit
- U355BCharge Air Cooler Outlet Pressure Sensor 2 Circuit
- U355CCharge Air Cooler Outlet Temperature Sensor Circuit
- U355FCathode Backpressure Valve Control Circuit
- U3560Cathode Backpressure Valve Position Sensor Circuit
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.