10
TM 5-3805-291-23-1
HOW TO USE ON-BOARD DIAGNOSTICS
THIS WORK PACKAGE COVERS
General, Understanding the Diagnostic Code Breakdown, Diagnostic Codes, Failure Mode Identifiers (FMIs)
INITIAL SETUP
Maintenance Level
References
Unit
Equipment Conditions
Test Equipment
Machine parked on level ground (TM 5-3805-291-
Test set, electronic systems (MSD) (Item 86, WP
10)
Work tool lowered to ground (TM 5-3805-291-10)
Tools and Special Tools
Parking brake engaged (TM 5-3805-291-10)
Adapter, test (Item 3, WP 0232 00)
Wheels chocked
Battery disconnect switch in OFF position (TM 5-
Software kit (Item 75, WP 0232 00)
3805-291-10)
Personnel Required
Engine start switch on OFF position (TM 5-3805-
291-10)
MOS 62B, Construction Equipment Repairer
GENERAL
The 966H Wheel Loader has four ECMs: Engine, Powertrain, Implement, and Messenger. Each ECM generates diag-
nostic fault codes indicating that an ECM has detected an electrical or electronic problem which may affect system perfor-
mance. Often, these codes are generated even before the operator notices a difference. If the operator notices a difference in
performance, the diagnostic code may indicate the cause of the problem.