Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Shut-off valve (Bi-fuel)
The rear electronic module (REM) (4/58) controls the shut-off valves, (8/88-90) (CNG) and (8/76) (LPG), via a relay (which supplies the valves with power when they should be open.
The rear electronic module (REM) receives information via the controller area network (CAN) from the engine control module (ECM) (4/46) indicating that the car should run on LPG or CNG. The rear electronic module (REM) also receives information via the controller area network (CAN) from the central electronic module (CEM) (4/56) indicating the position of the ignition and data about collision status. When the ignition is on and no collision has been registered, the rear electronic module (REM) activates the relay, which supplies the valves with power.
The rear electronic module (REM) deactivates the relay in the following cases:
- there is a signal from the engine control module (ECM) indicating that gasoline operation has been selected
- ignition off
- the collision status changes
- there is a fault in the communication on the controller area network (CAN).
The relay can be activated via a diagnostic command, for example, to allow the tank to be drained. Activation is carried out in VIDA via the vehicle communication socket. See function group 3, Rear Electronic Module (REM).
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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