PCM control can be divided into eight subsystems:
• Fuel Control
• Timing Control
• Glow Plug Control
• Boost Control
• EGR Control
• Cruise Control
• Transmission Control
• Diagnostic Request
The input-output relationship within the PCM isn’t one-to-one. The information from a particular input might be used as part of the PCM’s decision making for several outputs. For this reason, if one input fails, it can affect the operation of more than one system. Understanding these relationships can improve diagnostics.
Figures 5-3 through 5-10 show the PCM input/output relationship for the individual subsystems of the 6.5L EFI diesel engine.
