S07.10-0030-79
Block diagram |
B11/17 | Coolant temperature sensor | Y94/3 | Quantity control valve | |
B37/4 | Accelerator pedal module | A | Mercedes-Benz | |
B70/2 | Crankshaft Hall sensor | B | Nissan | |
N3/33 | CDI control unit | C | Default | |
Y76 | Fuel injectors | D | Optional |
Function requirements for deceleration fuel shutoff, general points
Circuit 87 ON (engine management ON)
Engine running.
Vehicle rolling.
Accelerator not operated
Vehicle is not in cruise control mode
Deceleration fuel shutoff, general
Deceleration fuel shutoff in deceleration mode of the engine has the following tasks:
increasing the braking effect of the engine.
reducing fuel consumption.
improving exhaust characteristics.
The CDI control unit (N3/33) performs a deceleration fuel shutoff dependent on the following sensors and signals:
Coolant temperature sensor (B11/17)
Accelerator pedal module (B37/4), accelerator pedal position
Crankshaft Hall sensor (B70/2), engine rpm
Deceleration fuel shutoff, function sequence
If the accelerator pedal is not actuated (zero quantity delivery), deceleration mode is triggered. The CDI control unit (N3/33) switches off the fuel injectors (Y76) in deceleration mode dependent on the coolant temperature, the engaged gear and at an engine speed > 1600/min.
The CDI control unit (N3/33) also lowers the fuel pressure in the rail via the quantity control valve (Y94/3). Upon operation of the accelerator pedal or a drop in the engine speed to < 1600 rpm, the CDI control unit (N3/33) again actuates the fuel injectors (Y76) and increases the fuel pressure in the rail via the quantity control valve.