Component description for CNG control unit - GF07.54-P-4000MRC
ENGINE 274.9 in MODEL 212 with CODE 924 (Bivalent natural gas drive)
Phantom view
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 with the ME-SFI [ME] control unit and directly over 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
- Circuit 15
- Circuit 31
- Circuit 87 M3
- GAS low-pressure and temperature sensor (B18/6)
- Gaseous fuel gas injection valve cylinder 1 (Y106/1) - actuation of ME-SFI [ME] control unit
- Gaseous fuel gas injection valve cylinder 2 (Y106/2) - actuation of ME-SFI [ME] control unit
- Gaseous fuel gas injection valve cylinder 3 (Y106/3) - actuation of ME-SFI [ME] control unit
- Gaseous fuel gas injection valve cylinder 4 (Y106/4) - actuation of ME-SFI [ME] control unit
- Gaseous fuel high-pressure sensor (Y107/2b1)
Direct output signals
- Gaseous fuel high-pressure sensor - sensor voltage (5 V)
- Gaseous fuel high-pressure sensor - sensor ground
- Gaseous fuel low pressure and temperature sensor - sensor voltage (5 V)
- Gaseous fuel low pressure and temperature sensor - sensor ground
- Gas injection valve gas for cylinder 1 (Y1061)
- Gas injection valve gas for cylinder 2 (Y1062)
- Gas injection valve gas for cylinder 3 (Y1063)
- Gas injection valve gas for cylinder 4 (Y1064)
- Gas reservoir 1 gas shutoff valve (Y107/1y1)
- Gas reservoir 2 gas shutoff valve (Y107/1y2)
- Gas reservoir 3 gas shutoff valve (Y107/1y3)
- Pressure regulating valve (Y107/2y1)
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)
Body
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 32-bit measurement and control electronics.
Voltage supply
The CNG control unit is activated via "terminal 15" by the ME-SFI [ME] control unit and supplied with power by "circuit 87 M3".
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).
Diagnosis
All actuators and sensors connected to the CNG control unit are diagnosed over the ME-SFI [ME] control unit. Recognized errors are sent by the CNG control unit to the ME-SFI [ME] control unit and stored there. Only the ME-SFI [ME] control unit responds in a service case. The CNG control unit cannot be directly read out.
| Designation | Unit | Values | Tolerance range | Remarks |
|---|---|---|---|---|
| CNG control unit (N118/2) | ||||
| Supply voltage | V | 12 | Terminal 87 M3 | |
| Reverse polarity protection | Yes | |||
| Short-circuit resistance | Yes | |||
| Flash capability/coding capability | Yes/yes | |||
| GAS low-pressure and temperature sensor (B18/6) | ||||
| Type | Combined pressure and temperature sensor | |||
| Supply voltage | V | 5.0 | From the CNG control unit | |
| Gas injection valve gas for cylinder 1 - 4 (Y106/1 - 4) | ||||
| Model | Solenoid valve | |||
| Supply voltage | V | 12 | Terminal 87 M3 | |
| Gas cylinder 1 - 3 gas shutoff valves (Y107/1y1 - 3) | ||||
| Model | Solenoid valve | |||
| Supply voltage | V | 12 | Terminal 87 M3 | |
| Gaseous fuel high-pressure sensor (Y107/2b1) | ||||
| Model | Pressure sensor | |||
| Supply voltage | V | 5.0 | From the CNG control unit | |
| Pressure regulating valve (Y107/2y1) | ||||
| Model | Solenoid valve | |||
| Supply voltage | V | 12 | Terminal 87 M3 |
| Wiring diagram for CNG gaseous fuel injection system control unit | N118/2 | PE07.54-P-2102-97DAA |