Honda TRX680FA Service Manual page 46

TECHNICAL FEATURES
PCM (POWERTRAIN CONTROL MODULE)
The engine and drivetrain systems of this model are controlled by the PCM; the ECM (Engine Control Module) and TCM
(Transmission Control Module) are integrated into the PCM.
The PCM controls the following systems:
• Engine management system
- PGM-FI system
- Ignition system
- Cooling fan control system
• Drivetrain system
- A/T (Automatic Transmission) system
- Selectable 4WD system
PCM
PGM-FI SYSTEM
This PGM-FI system for the ATV is composed of the fuel pump, throttle body and its electronic control system by PCM.
This system controls and manages the engine operation, and enhances the emission control performance, fuel economy,
starting performance and driveability when compared to a conventional carburetor.
DRIVETRAIN SYSTEM
This manual describes the A/T system and selectable 4WD system as "drivetrain" system. The PCM controls the front final
clutch located in the differential by selecting the 2WD/4WD switch. The PCM also controls the A/T system as described in
AUTOMATIC TRANSMISSION system feature (page 2-7).
SELF-DIAGNOSTIC FUNCTION
The PCM has a fail-safe function and also a self-diagnostic function for the PGM-FI, A/T and selectable 4WD system. Some
detection items (sensors, etc..) are shared by the PGM-FI and drivetrain systems and so their failure may affect the opera-
tion of both systems.
If both PGM-FI and DRIVETRAIN DTCs are indicated at the same time, troubleshoot the PGM-FI system first then check all
DTCs again.
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