L9407F

8/11

Table 1. FAULT DETECTION TABLE

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

Figure 6. Output Voltage rise/fall time (DF, DF_MON)

Figure 7. Lamp on delay at Ign. switch turn on

Root Cause

Signal

Effect

Test detect

Alternator belt breaking

PH

Alternator disexcitation

VPH<VPHH & VA+<Vreg

Brushes open

PH

Alternator disexcitation

VPH<VPHH & VA+<Vreg

Driver Open

PH

Alternator disexcitation

VPH<VPHH & VA+<Vreg

Field interruption

PH

Alternator disexcitation

VPH<VPHH & VA+<Vreg

Field short circuit to the battery

PH

Alternator disexcitation

VPH<VPHH & VA+<Vreg

Field short circuit to the ground

DF

Overvoltage

DF<VS1 & VA+>Vreg

Battery discharge (Field Driver open)

A+

Undervoltage

VA+<Vreg

No fully excited

A+

Undervoltage

VA+<Vuv

Battery discharge

A+

Undervoltage

VA+<Vuv

90%

10%

t-RISE

t-TM

t-FALL

t-TD

DF

DF_MON

Voltage

Ign. sw

W/Lamp

Off

Off

On

On

L-t-D