- Product description
The Ventrex OE A2424700407 pressure regulator is a two-stage electronic component used in the natural gas systems of Mercedes vehicles. It is homologated according to the ECE R110 standard and is designed to safely handle the high pressures of compressed natural gas (CNG) by reducing them to a level compatible with the operation of the injectors (around 5-9 bar absolute).
Manufactured from a high-strength metal alloy, it has several functional connections:
- High pressure methane inlet
- Output to the injector rail
- Two connections for the coolant circuit
- Electrical plug connections for the control solenoid valve (N372) and the integrated pressure sensor (G400)
Most common failures and defects
Despite the advanced architecture, the pressure reducer can exhibit various problems over time. Below are the most common defects observed with this component.
Gas leak or pressure drop
Even though the rubber diaphragms are less prone to cracking than mechanical models, seals and valve seats can wear out over time and cause leaks. Typical symptoms are
- Perceptible odour of gas outside or inside the vehicle interior
- Hissing noises when the bonnet is open
- Unusual switching from natural gas to petrol when accelerating
- Pressure drops when power is required
Icing of the pressure reducer
In cold environments or when the engine has just been started, the formation of ice on the outside of the pressure reducer may indicate a lack of circulation of the coolant. Possible causes:
- Air in the cooling circuit
- Blockage or malfunction of the water pump
- Ageing of the seals due to low temperatures
Icing can lead to an interruption in the natural gas supply and a forced switchover to petrol.
Defect in the control solenoid valve (N372)
The solenoid valve can block in the closed position (no flow) or in the open position (excessive pressure). Both states impair system reliability and lead to a safety intervention by the engine control unit, which temporarily deactivates the natural gas supply.
Integrated pressure sensor (G400)
This sensor measures the pressure on the high-pressure side of the CNG system. In the event of a malfunction, it can:
- generate incorrect displays of the natural gas level
- activate the CNG indicator light or the engine indicator light
- store error codes in the control unit
Symptoms to be monitored
To avoid serious damage, the following symptoms should be monitored:
- Starting difficulties in natural gas mode, especially after long periods of inactivity
- Switching to petrol while driving without driver intervention
- Rime or ice formation on the pressure reducer
- Persistent odour of natural gas
- Loss of power when the engine is cold
During maintenance work, it is recommended
- Check the correct circulation of the coolant
- Visually check hoses and connections
- If present, replace the gas filter regularly to avoid contamination in the system
Conclusion
The Ventrex OE A2424700407 CNG pressure regulator is a modern and technologically advanced solution for CNG-powered Mercedes vehicles. Although it offers performance improvements over older mechanical systems, it requires proper attention and maintenance to ensure longevity and safety.