What it means
Generic fault on the inlet pressure sensor 2 of the expander (turbine recovering energy from the cathode exhaust on FCEVs).
At a glance
- Usually lights the warning light of the system that lost communication
How it works
Expander inlet pressure sensor 2 measures pressure at the inlet of the cathode-exhaust energy-recovery expander. The control module monitors sensor 2's data path and sets this code when communication or the reported signal from this specific sensor fails.
Common causes
Most likely first.
- Sensor failed
- Gateway module routing CAN messages incorrectly
- CAN 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
How to diagnose it
- Record freeze-frame data and scan all modules for communication faults to determine whether the issue is limited to expander inlet pressure sensor 2.
- Check live data from sensor 2 against sensor 1 and current operating conditions for a missing or implausible reading.
- Inspect sensor 2's connector and wiring at the expander inlet for loose pins, corrosion, moisture, or physical damage.
- Measure sensor 2's power, ground, and signal circuits against the manufacturer's specification.
- If other devices also have communication faults, check gateway routing and CAN network integrity, including terminating resistance, to the manufacturer's specification.
Common fixes
- Repair or secure damaged wiring to expander inlet pressure sensor 2.
- Clean or repair corroded terminals at sensor 2.
- Replace expander inlet pressure sensor 2 if circuit checks pass and its data remains faulty.
- Repair any confirmed gateway or CAN network problem.
Can I keep driving?
If warnings are accompanied by reduced power or unstable fuel-cell operation, avoid continued or high-load driving and stop safely if a shutdown warning appears. Arrange prompt diagnosis because the controller may limit system output when sensor 2 data is unavailable.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.