Isuzu KB P190. Service manual - part 904

Starting System – V6 

Page 6D1-2–8 

 

2.4 Wiring 

Diagram 

 

Figure 6D1-2 – 2 

Starting System – V6 

Page 6D1-2–9 

 

 

Figure 6D1-2 – 3 

Starting System – V6 

Page 6D1-2–10 

 

2.5 

Starting System Inoperative / 
Malfunctioning 

Circuit Description 

The battery cable supplies a constant connection from the battery to starter solenoid connector P – 4. 

When the ignition switch is turned to the START position, 12 V is applied to the ECM connector C – 56 pin 31. 

For vehicles with 4 speed automatic transmission, when the transmission is in park (P) or neutral (N), the park / neutral 
and back-up switch grounds ECM connector C – 56 pin 32. 

The ECM provides a ground for the start relay, ECM connector C – 56 pin 35 to start relay connector X – 13 pin 5.  

When activated the start relay provides 12 V to starter solenoid connector P – 3 pin 1. 

The solenoid closes its switch contacts to connect the battery voltage at the solenoid switch terminal P – 4 terminal B to 
the DC motor. The pull-in winding of the solenoid switch is grounded through the DC motor winding and brushes. The 
hold-in winding is grounded through the solenoid casing. The DC motor is grounded through the starter motor casing. 

Refer to 2.4 

Wiring Diagram to aid in diagnosis. 

Diagnostic Table Notes 

Reference to following information will assist when diagnosing starting circuit faults: 

1 

If the battery, starter motor and fuel system are deemed as serviceable and a ‘no crank’ and / or ‘no start’ condition 
exists, refer to the following Sections as required: 

a 

11A Immobiliser for theft deterrent engine crank inhibitor related faults 

b 

6C1-2 Engine Management V6 Diagnostics, for starter relay circuit faults 

2 

For all wiring harness fault diagnoses, refer to 8A Electrical Body and Chassis. 

3 

For wiring harness repairs, refer to 8A Electrical Body and Chassis. 

4 

Refer to 8A Electrical Body and Chassis for harness routing. 

5 

Ensure the battery, cables and connections are in good order. Refer to 8A Electrical Body and Chassis. 

Diagnostic Table 

Step Action 

Yes 

No 

1 

Did you review 1.3 

System Operation? 

Go to Step 2 

Go to 1.3

 System 

Operation 

2 

Did you read 2.3  Diagnostic Systems Check 

Go to Step 3 

Go to 2.3

 Diagnostic 

Systems Check 

3 

Turn the ignition switch to the START position and then release it. 

Did the engine crank or were there any clicking or chattering sounds 
from the solenoid? 

Go to Diagnostic 

Table – Slow 

Cranking, Solenoid 

Clicks or Chatters 

Go to Step 4 

4 

Inspect fusible link SBF9, refer to 8A Electrical Body and Chassis. 

Is fusible link SBF9 blown? 

Replace the faulty 

fusible link (refer to 

Note 3). 

If the fusible link 

blows again, repair 

or replace the circuit 

from SBF9 to the 

starter relay X – 13 

pin 1 or ignition 

switch B – 62 pin 2 

(refer to Note 2) 

Go to Step 5 

Starting System – V6 

Page 6D1-2–11 

 

Step Action 

Yes 

No 

5 

Inspect fusible link SBF1, refer to 8A Electrical Body and Chassis. 

Is fusible link SBF1 blown? 

Replace the faulty 

fusible link (refer to 

Note 3). 

If the fusible link 

blows again, repair 

or replace the circuit 

from SBF1 

connection P – 7 

and engine 

compartment fuse 

panel connector B – 

63 pin 3, (refer to 

Note 2) 

Go to Step 6 

6 

Inspect fuse SBF5, refer to 8A Electrical Body and Chassis. 

Is fuse SBF5 blown? 

Replace the faulty 

fuse (refer to 

Note 3). 

If the fuse blows 

again, repair or 

replace the circuit 

from SBF5 to the 

cabin fuse panel 

connector C – 108 

pin 2 (refer to 

Note 2) 

Go to Step 7 

7 

Inspect fuse C20, refer to 8A Electrical Body and Chassis. 

Is fuse F15 blown? 

Replace the faulty 

fuse (refer to 

Note 3). 

If the fuse blows 

again, repair or 

replace the circuit 

from fuse C20 to the 

ECM connector C – 

56 pin 31 (refer to 

Note 2) 

Go to Step 8 

8 

N O T E  

On automatic vehicles ensure that park (P) or neutral (N) is 
selected. 

Turn the headlamps on. 

Turn the dome lamps on. 

Turn the ignition switch to the START position. 

Do the lamps dim? 

Go to Step 9 

Go to Step 10 

9 

Perform the 3.3  On-Vehicle Testing. 

Did you correct the condition? 

 

Go to Step 21 

Go to Step 2