What it means
Hydrogen Tank B Valve Enable Circuit: an electrical fault is present in the circuit.
At a glance
- Usually lights the warning light of the system that lost communication
- The engine or gearbox may go into limp mode
How it works
The Tank B valve enable circuit provides the electrical permission needed for the valve control system to operate. This code sets when that enable path has an electrical fault, such as an open wire or failed relay, and the Tank B valve may not be enabled.
Common causes
Most likely first.
- Enable wire open or relay 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 communication, relay, or supply faults.
- Check live data for the Tank B valve enable command and status, if available, to establish whether the controller is requesting enable.
- With the vehicle safely powered down according to its service instructions, inspect the Tank B enable wiring, connectors, and relay area for loose, corroded, or damaged connections.
- Test the enable fuse, relay operation, and circuit continuity using the manufacturer's wiring diagram and specification.
- If communication codes affect multiple modules, have gateway routing and CAN network termination checked against the manufacturer's specification.
- If the enable path tests correctly, verify the Tank B valve enable input and related control operation using the manufacturer's procedure.
Common fixes
- Reconnect or repair an open or damaged Tank B enable wire or connector.
- Replace a failed fuse or enable relay after confirming the circuit is sound.
- Correct a gateway routing fault or repair a CAN network defect if confirmed.
- Repair the Tank B valve enable input or control hardware if it fails the specified test.
Can I keep driving?
The valve may not be enabled, and the vehicle can enter reduced-power mode or shut down; avoid normal trips and stop safely if warnings or power loss increase. Arrange prompt diagnosis and do not work on the hydrogen system yourself.
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.