308C Excavator Electrical and Electronic System – Controller – Troubleshoot

Problem: The controller is not functioning properly.

Solution: Check that the following connectors and components are connected properly: “CONN 2”, “CONN 40”, “CONN 44”, “CONN 45”, “CONN 46” and “CONN 47”. If the problem still exists, use the following procedure to troubleshoot the system.

Illustration 1 g00854929
Table 1
Low idle switch (OFF)    
Connect jumper cable across terminals:     Connect positive lead of multimeter to terminal:     Connect negative lead of multimeter to terminal:     Expected result:    
CONN 45 (6) to (3)     CONN 45 (1)     CONN 45 (2)     +18 V or more    
CONN 45 (6) to (4)     CONN 45 (1)     CONN 45 (2)     -18 V or less    
CONN 45 (6) to (5)     CONN 45 (1) to (2) – Either polarity     0 V    
Table 2
Low idle switch (ON)    
Connect jumper cable across terminals:     Connect positive lead of multimeter to terminal:     Connect negative lead of multimeter to terminal:     Expected result:    
CONN 45 (6) to (3)     CONN 45 (1) to (2) – Either polarity     0 V    
CONN 45 (6) to (4)     CONN 45 (1)     CONN 45 (2)     -18 V or less    
CONN 45 (6) to (5)     CONN 45 (1)     CONN 45 (2)     +18 V or more