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L9911

Figure 13. Soft Start/attack Characteristics

Table 10. Fault Detection

The diagnostic result is disabled during the Soft-start delay time t_ST 0...3 and the soft-start / soft attack timing t_SL 0...3

Figure 14. DFMonitor Electrical configuration

Root Cause

Signal

Effect

Test detect

Alternator belt breaking

P

Alternator disexcitation

VP<VPHH1 & VB+<Vreg

Brushes open

P

Alternator disexcitation

VP<VPHH1 & VB+<Vreg

Field Driver Open

P

Alternator disexcitation

VP<VPHH1 & VB+<Vreg

Field interruption

P

Alternator disexcitation

VP<VPHH1 & VB+<Vreg

Field short circuit to the battery

F+

Overvoltage

VF+>VS1 & VB+ > Vov-d

Field short circuit to the ground

P

Alternator disexcitation

VP<VPHH1 & VB+<Vreg

Battery discharge

B+

Undervoltage

VB+<Vuv

Engine

Ign. Switch

W/Lamp

Ifield

F+/DFM

off

on

off

on

off

on

t_SL

t_ST

Field Pre-

excitation

Field

Regulation

Load ON

L9911

Control

Circuit

Field driver

DFMon driver

to the ECU

R

Valim

Test circuit

Field

Alternator

Regulator assy

B+

F+

DFM