Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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System Protection

Power to the compressor clutch may be cut should either the engine management or air conditioning control systems detect certain conditions; these conditions may be caused by Fault or Demand and can be classified thus:

Fault
- Engine coolant overheat.
- Refrigerant excessive pressure.
- Refrigerant, insufficient pressure or low charge weight.
- Speed differential between compressor and crankshaft caused by belt slippage or compressor seizure (indicated by A/C state lamp flashing once per second)-12 cylinder engine only. This feature is called, 'lock sensing'.

Demand
- Engine maximum power requirement
- Electrical system drain at engine idle.