GF07.16-P-2001GZ CDI Starting, Function

GF07.16-P-2001GZ CDI Starting, Function

During start-up via the CDI control unit (N3/9), the Common Rail Diesel Injection (CDI) controls the following functions:
- Preglowing
- Actuation of fuel pump (M3)
- Start-readiness glowing
- Starter control
- Synchronization of the injection sequence
- Start-glowing
- Start quantity control
- Afterglowing

Preglowing
For the start it is necessary to heat glow plugs (R9) to a temperature, which heats the combustion chambers and which enables fuel to ignite at the designated time.

Actuation of fuel pump (except for model 463)
The CDI control unit controls the fuel pump using the integral fuel pump relay (F4kO) in the rear SAM control unit (N10/8). The following prerequisites must exist:
- "Engine start" from drive authorization system stage 3 (DAS 3)
- Circ. 50 ON
- Selector lever position "P" or "N"

Actuation of fuel pump (only for model 463)
The CDI control unit actuates the fuel pump over the integral fuel pump relay (N10/2kA) in the rear signal acquisition and actuation module (SAM) (N10/2). The following prerequisites must exist:
- "Engine start" from drive authorization system stage 3 (DAS 3)
- Circ. 50 ON
- Selector lever position "P" or "N"

Start-readiness glowing
This ensures that a sufficiently high combustion chamber temperature is available from preglowing through to engine start.

Starter control (except for model 463)
The CDI control unit actuates the starter (M1) via the integral starter relay (F58kI) in the rear SAM control unit depending on the following information:
- From the EIS control unit (N73) the start enable information from DAS 3
- Circ. 50 ON
- Selector lever position "P" or "N"

Starter control (only for model 463)
The CDI control unit actuates the starter (M1) via the integral starter relay (N10/1kS) in the rear signal acquisition and actuation module (SAM) (N10/2) based on the following information:
- From the EIS control unit (N73), the start enable information from DAS 3
- Circ. 50 ON
- Selector lever position "P" or "N"

Synchronization of the injection sequence
In order to achieve correct assignment of the injection sequence to the respective cylinder, the sequence is synchronized during the first engine revolutions. For detection of cylinder 1, the CDI control unit requires the signal from the camshaft Hall sensor (B6/1) and the signal from the crankshaft Hall sensor (B70).

Start-up glowing
During start-up, the first working cycles and ramp up of the engine are supported by this function.

If no signal is supplied by the camshaft Hall sensor when the engine is started, the engine does not start.

Start quantity control
During engine start, the CDI control unit, depending on the coolant temperature and the engine speed, calculates the start quantity and then actuates the quantity control valve (Y94), the pressure regulator valve (Y74) and the fuel injectors (Y76) accordingly.

Afterglowing
Combustion is supported by this function following a successful engine start according to performance mapping.