What it means
The control circuit of alternative fuel tank shutoff valve D reports a control circuit performance/stuck off condition. Tank isolation cannot be commanded as expected on multi-tank CNG/LPG systems.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
- The engine or gearbox may go into limp mode
How it works
Shutoff valve D isolates tank D in a multi-tank CNG or LPG system when the control module commands it. For this code, the circuit is not simply reported open or at an abnormal voltage: the module detects that valve D does not respond as expected and appears stuck off. A mechanically stuck valve, weakened coil force, or debris can prevent the commanded movement.
Common causes
Most likely first.
- Shutoff valve mechanically stuck closed
- Coil force degraded with age
- Carbon or debris buildup preventing free movement
Symptoms
- Check-engine light
- Alternative-fuel warning light
- Difficulty switching fuel modes
How to diagnose it
- Record freeze-frame data and use a scan tool to check whether valve D's commanded state changes when the fault occurs.
- Inspect valve D's connector and harness for damage or poor contact that could prevent the command from reaching the valve.
- Check the valve D coil and its control circuit against the manufacturer's specification to rule out an electrical supply or coil problem.
- Use the manufacturer's approved test to verify whether valve D responds mechanically to a command; do not apply power directly unless that procedure permits it.
- If electrical checks pass but valve D remains off, inspect or service the valve for sticking or internal debris as directed by the manufacturer.
Common fixes
- Restore a loose or damaged valve D electrical connection.
- Repair the valve D control circuit if testing finds an electrical fault.
- Service valve D if the approved procedure confirms sticking or debris.
- Replace valve D if its coil has weakened or the valve cannot move reliably.
Can I keep driving?
Because tank D may not respond to isolation commands, fuel switching and tank availability may be affected. Follow the vehicle's warnings and stop using alternative fuel if the system indicates that operation is restricted.
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.