What it means
Generic fault on charge air cooler outlet pressure sensor 1 (after CAC, before stack on FCEV air path).
At a glance
- Usually lights the warning light of the system that lost communication
How it works
Charge air cooler outlet pressure sensor 1 measures pressure after the cooler and before the fuel-cell stack air inlet. The controller uses its signal to monitor air-path conditions; this circuit code indicates an electrical or communication fault affecting sensor 1.
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 related pressure-sensor circuit and communication codes.
- Compare sensor 1's live pressure reading with sensor 2 and other available air-path readings under similar conditions, looking for a missing or implausible value.
- With the vehicle powered down as specified, inspect the sensor 1 connector and wiring at the charge air cooler outlet for damage, corrosion, or a loose connection.
- Check sensor 1's supply, ground, and signal circuit using the manufacturer's wiring diagram and specification.
- If multiple modules report communication faults, have the gateway and CAN network termination checked against the manufacturer's specification.
- If the circuit is sound, test sensor 1 and its pressure passage according to the manufacturer's procedure.
Common fixes
- Reconnect or repair the charge air cooler outlet sensor 1 connector or wiring.
- Repair a confirmed supply, ground, or signal-circuit fault.
- Correct a gateway routing issue or CAN network defect if testing confirms one.
- Replace pressure sensor 1 if it fails the specified test.
Can I keep driving?
A faulty sensor 1 signal can affect fuel-cell air-path monitoring and may bring on warnings or altered operation, although limp mode is not specifically indicated. Avoid heavy demand if performance changes and arrange diagnosis 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.