Mercedes-Benz M 447 hLAG User Manual

Functional Description of EGM
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Status September 2003 (EvoBus-Service / AFT) Page: 22 of 83
2.2.1.8 Engine protection: gas injection
From the software version 13A, the EGM engine control unit is capable of detecting fault states on the
gas injectors and their wiring. In the case of a fault, corresponding fault codes are stored in the fault
memory and emergency running measures are initiated. As full engine output is not possible in the case
of a failure of individual gas injectors, this is intentionally limited in dependence on the number of failed
gas injectors and the engine speed. The EGM engine control unit is capable of compensating the failure of
up to three "gas injector pairs"; if an additional injector pair fails, the engine is switched off.
Engine protection: gas injection
Fault on Gas Injector Measures
Æ Break in wiring
Æ Interturn fault
- Torque reduction: 20 % per failed "injector pair"
- The actuation of the corresponding "injector pair" is deactivated
- Ignition remains completely switched on (all cylinders)
- Lambda control remains switched on
Fault on Bank Supply Measures
Æ Break in wiring
Æ Short circuit to ground
- Torque reduction: 20 % per failed "injector pair"
- The actuation of the corresponding "injector pairs" is deactivated
- Ignition remains completely switched on (all cylinders)
- Lambda control remains switched on
Title: Diagnosis of gas injeciton (Cyl. 1-6),
Ub short-circuit, short-circuit to ea rth, break in wiring
File:
kd_hwd_eingasung_übersicht.vsd
Date of last change: 2001-08-22
Gas injector actuation of engine control
+ -
B attery
+ -
B attery
Ub short-circuit
S hort-circuit to ea rth
Bank supply
L. probe switch 1
L. probe switch 3
L. probe switch 2
+ -
B attery
+ -
B attery
S hort-circuit to e arth
Ub short-circuit
Break in wiring
Break in wiring
bank-selective detection
valve-selective detection
Interturn fault
- no detection
- C ontrol unit destruction
no detection
no detection

Mercedes-Benz M 447 hLAG Specifications

General

Brand	Mercedes-Benz
Model	M 447 hLAG
Category	Engine
Language	English