What it means
Generic electrical fault on the air inlet pressure sensor of the fuel cell air supply (cathode side, before compressor).
At a glance
- Usually lights the warning light of the system that lost communication
How it works
The air inlet pressure sensor measures pressure on the fuel-cell cathode air path before the compressor. The control system uses this reading to manage air supply; this circuit code indicates an electrical or communication fault affecting that sensor signal.
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
- Save freeze-frame data and scan all modules for sensor-supply, circuit, and communication codes before clearing them.
- Compare the air inlet pressure reading with other available air-path data under the recorded conditions, and check whether it is missing or implausible.
- With the vehicle powered down as specified, inspect the pre-compressor air inlet pressure sensor connector and harness for damage, moisture, corrosion, or poor contact.
- Check sensor reference, ground, and signal circuits using the manufacturer's wiring diagram and specification.
- If several modules show communication faults, have gateway routing and CAN termination checked against the manufacturer's specification.
- If wiring and communication are sound, test the air inlet pressure sensor and its pressure passage according to the manufacturer's procedure.
Common fixes
- Reconnect or repair damaged air inlet pressure sensor wiring or terminals.
- Repair a confirmed sensor reference or ground fault.
- Correct a gateway routing problem or CAN network fault if testing identifies one.
- Replace the air inlet pressure sensor if it fails the specified test.
Can I keep driving?
This fault may affect fuel-cell air management and can bring on warning lights or reduced operation, though limp mode is not specifically indicated. Avoid demanding operation if performance changes, and have the sensor circuit checked soon.
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.