Overrun Mode Fuel Shutoff, Basic Function - GF07.10-P-1049A
Engine All (4xWD)
Engine All (CAR)
Overview
This document contains information on:
- General
- Function requirements
- Function
General
In order to reduce fuel consumption, increase the braking effect of the combustion engine and improve the exhaust characteristics, the overrun mode fuel shutoff interrupts the fuel supply to the combustion engine under certain driving conditions. The combustion produces no further output so that the vehicle is only rolling.
Function requirements
- Engine management ON (circuit 87M)
- Engine in operation
- Accelerator not operated
- Transmission position D or R engaged
- Transmission position N engaged (when the vehicle is at a standstill or rolling)
- Speed control or distance control not active
- Not too high an exhaust temperatures
Function
If the accelerator pedal is not operated, the overrun mode fuel shutoff automatically comes into operation.
The combustion engine control unit no longer actuates the fuel injectors, depending on the input signals of the coolant temperature, selector lever position and engine speed. With a diesel engine, the combustion engine control unit reduces the fuel quantity and accordingly the fuel pressure in the fuel distributor, also via the quantity control valve.
When the accelerator pedal is operated, the combustion engine control unit actuates the fuel injectors again. With a diesel engine, the combustion engine control unit also increases the fuel quantity and the fuel pressure in the fuel distributor via the quantity control valve.
| Function schematics | |||
| Function schematic for overrun mode fuel shutoff | Engine 176, 177 in model 167 Engine 177 in model 290 as of model year 2021 | PE07.10-P-2508-97B | |
| Engine 260, 282, 608 in model 118, 177, 247 Engine 264 in model 167 | PE07.10-P-2508-97C | ||
| Engine 654 in model 118, 177, 247 Engine 654 in model 213, 238, 257 as of model year 2021 Engine 654, 656 in model 167 | PE07.10-P-2508-97D | ||
| Engine 256 in model 167 Engine 256 in model 213, 238 as of model year 2021 Engine 264 in model 213, 238, 257 as of model year 2021 | PE07.10-P-2508-97E | ||
| Engine 139 in model 118, 177, 247 | PE07.10-P-2508-97F | ||
| Engine 254 in model 206, 214, 236, 254 Engine 256 in model 214, 223, 236 | PE07.10-P-2508-97G | ||
| Engine 176 in model 223 | PE07.10-P-2508-97H | ||
| Engine 279 in model 223 | PE07.10-P-2508-97I | ||
| Engine 139 in model 192, 206, 232, 236, 254 | PE07.10-P-2508-97J | ||
| Engine 654 in model 206, 214, 236, 254 Engine 656 in model 223 | PE07.10-P-2508-97K | ||
| Engine 177 in model 192, 223, 232 | PE07.10-P-2508-97L | ||
| Engine 274 in model 213 as of model year | PE07.10-P-2508-97M | ||
| Engine 656 in model 464 | PE07.10-P-2508-97N | ||
| Additional basic functions | |||
| Combustion engine control unit, basic function | GF07.08-P-9890A |