U3567Anode Inlet Pressure Sensor 2 Circuit
- Generic OBD-II code · Network
- Turns on the check-engine light
- Can trigger limp mode
- How the car detects it
- U3567 belongs to the second pressure sensor at the anode inlet. Its signal carries safety weight: GM uses anode pressure to catch an injector stuck open, then shuts the tank valves, opens the anode bleed valve, lifts cathode pressure with compressor and backpressure valve and opens the cathode bypass so hydrogen in the exhaust stays diluted. Another GM patent treats a gap of more than a calibrated margin, typically 3 kPa, between actual and desired pressure as an injector fault. Sensors in this wet zone can ice up, so GM checks the anode sensor before start against ambient pressure plus the anode-to-cathode differential. A second sensor allows a similar comparison while driving. No maker publishes U3567. Expect a warning; with sensor 1 as the only source, power may be reduced. Sensor 1 is U3566.
- What you may notice
- Fuel cell system warning, MIL on
- Often no noticeable change while sensor 1 still works
- Reduced power
- Likely causes
- LikelyOpen, short or corrosion in wiring or connector of sensor 2 at the stack
- PossibleAnode inlet pressure sensor 2 faulty internally
- RareWater in the connector, fault mainly after frost
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €150 – €1,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.