Component description for CNG control unit - GF07.54-P-4000MFG
ENGINES 271.958 in MODEL 212.041 with CODE (924) Bivalent natural gas drive
Right front view of engine compartment
Location
The CNG control unit is located in the front right wheel well.
Task
The CNG control unit controls the fuel injection and gas injection in connection with the ME-SFI [ME] control unit (N3/10). To do this, it is networked directly with the ME-SFI [ME] control unit and indirectly via the drive train sensor CAN (CAN I). The CNG control unit CNG also controls and monitors the complete gas system in the vehicle.
Input and output signals
The CNG control unit evaluates the following input signals and sends the corresponding output signals:
- Direct input signals
- Direct output signals
- CAN input signals
- CAN output signals
Direct input signals
- Terminal 15
- Circuit 31
- Circuit 87M1
- Gas high pressure sensor (B18/1)
- Gas low pressure sensor (B18/2)
- Gas temperature sensor (B50/3)
- Injection valve for cylinder 1 (Y62/1) or gas injection valve gas for cylinder 1 (Y106/1) - actuation of the ME-SFI [ME] control unit
- Injection valve for cylinder 2 (Y62/2) or gas injection valve gas for cylinder 2 (Y106/2) - actuation of the ME-SFI [ME] control unit
- Injection valve for cylinder 3 (Y62/3) or gas injection valve gas for cylinder 3 (Y106/3) - actuation of the ME-SFI [ME] control unit
- Injection valve for cylinder 4 (Y62/4) or gas injection valve gas for cylinder 4 (Y106/4) - actuation of the ME-SFI [ME] control unit
Direct output signals
- Gas high pressure sensor - sensor voltage (5 V)
- Gas high pressure sensor - sensor ground
- Gas low-pressure sensor - sensor voltage (5 V)
- Gas low pressure sensor - sensor ground
- Gas temperature sensor - sensor ground
- Cylinder 1 injection valve (Y62/1)
- Cylinder 2 injection valve (Y62/2)
- Cylinder 3 injection valve (Y62/3)
- Cylinder 4 injection valve (Y62/4)
- Gas injection valve gas for cylinder 1 (Y106/1)
- Gas injection valve gas for cylinder 2 (Y106/2)
- Gas injection valve gas for cylinder 3 (Y106/3)
- Gas injection valve gas for cylinder 4 (Y106/4)
- Gas shutoff valve for gas cylinder 1 (Y107/1y1)
- Gas shutoff valve for gas cylinder 2 (Y107/1y2)
- Gas shutoff valve for gas cylinder 3 (Y107/1y3)
- Gas safety shutoff valve (Y107/2)
CAN input signals
ME-SFI [ME] control unit
- Diagnosis requests
- Engine load
- Engine speed
- Coolant temperature
- Exchange regarding operating mode (gasoline/gas)
CAN output signals
ME-SFI [ME] control unit
- Diagnostic data
- Injection adjustment
- Status of the gas system
- Gas cylinder fill level
- Exchange regarding operating mode (gasoline/gas)
Design
The housing of the CNG control unit is made of diecast aluminum and the cover is made of corrosion-proof sheet steel. The CNG control unit is water proof and dust proof.
It contains 16-bit measurement and control electronics.
Power supply
With ignition ON, the CNG control unit is supplied with voltage from "circuit 15 fused".
In the operating voltage range it has both short-circuit protection and reversed polarity protection.
Ground connection
The ground connection "circuit 31" takes place over the wheel arch ground point at the front right (W3/1).
| Designation | Unit | Values | Tolerance range | Remarks | |
|---|---|---|---|---|---|
| CNG control unit (N118/2) | |||||
| Supply voltage | V | 12 | |||
| Voltage limit: | minimum | V | 6.0 | ||
| maximum | V | 16 | |||
| Working temperature | °C | -40 - +90 | |||
| Reverse polarity protection | Yes | ||||
| Short-circuit resistance | Yes | ||||
| Flash capability/coding capability | Yes/yes | ||||
| Gas high pressure sensor (B18/1) | |||||
| Model | Pressure sensor | ||||
| Supply voltage | V | 5.0 | From the CNG control unit | ||
| Output signal: | minimum | V | 0.5 | ||
| maximum | V | 4.6 | ±0.1 V | ||
| Measuring range | bar | 260 | |||
| Gas low pressure sensor (B18/2) | |||||
| Model | Pressure sensor | ||||
| Supply voltage | V | 5.0 | From the CNG control unit | ||
| Operating current | mA | < 15 | |||
| Output signal: | minimum | V | 0.5 | ||
| maximum | V | 4.5 | |||
| Output current | mA | 4 | |||
| Measuring range | bar | 0 - 10 | |||
| Gas temperature sensor (B50/3) | |||||
| Model | NTC resistor N egative T emperature C oeffizient (NTC thermistor) |
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| Ground supply | From the CNG control unit | ||||
| Measuring range | °C | -40 - 150 | |||
| Injection valves for cylinder 1 to 4 (Y62/1 - Y62/4) | |||||
| Model | Solenoid valve | ||||
| Supply voltage | Circuit 87M1 | ||||
| Coil resistance | Ω | approx. 14.5 | at 20°C | ||
| Gas injection valves gas for cylinders 1 - 4 (Y106/1 - 4) | |||||
| Model | Solenoid valve | ||||
| Switch-on current limited to | A | 4 | |||
| Permanent current | A | 2 | |||
| Supply voltage | V | 12 | Circuit 87M1 | ||
| Gas shutoff valves Gas cylinder 1 - 3 (Y107/1y1 - 3) |
|||||
| Model | Solenoid valve | ||||
| Supply voltage | V | 12 | Circuit 87M1 | ||
| Gas safety shutoff valve (Y107/2) | |||||
| Model | Solenoid valve | ||||
| Supply voltage | V | 12 | Circuit 87M1 | ||
| Resistor | Ω | 11.1 | ±6% | ||
| Special features | Normally closed | ||||
| Wiring diagram for CNG gas injection system control unit with ME-SFI [ME] gasoline injection system | N118/2 | PE07.54-P-2101-97DAA |