What it means
Hydrogen Tank B Valve Performance: the component is electrically intact but its response does not match the command.
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
Tank B’s valve regulates hydrogen flow from that tank when commanded by the fuel-cell system. The controller sets this code when the valve’s electrical circuit appears intact but its response does not match the requested operation.
Common causes
Most likely first.
- Valve stuck mechanically
- 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 related network codes to determine whether the issue is confined to Tank B.
- Compare Tank B valve command and reported response in live data, if available, and note the conditions when they diverge.
- With the vehicle safely powered down under its service instructions, inspect the Tank B valve connector and wiring for damage, corrosion, or looseness.
- Have a technician confirm that the gateway routes Tank B valve command and status messages correctly.
- If network codes are present, have CAN communication and terminating resistance checked against the manufacturer's specification.
- If wiring and communications are sound, have the Tank B valve checked for mechanical sticking using the manufacturer's procedure.
Common fixes
- Repair a loose, damaged, or corroded Tank B valve connection or wiring.
- Correct a gateway communication-routing fault.
- Repair the CAN network or replace an out-of-spec termination component as specified.
- Repair or replace the sticking Tank B valve.
Can I keep driving?
A Tank B valve that does not respond properly can cause reduced power or system shutdown, so avoid relying on the vehicle for routine travel and stop safely if the condition worsens. Have it checked promptly; do not dismantle hydrogen plumbing or high-pressure parts.
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.