Operation CHARM: Car repair manuals for everyone.

A/C Load Signal

The A/C load circuit signals the ECM when the A/C compressor system is under an excessive load during, for example, any high ambient conditions. If the system pressure exceeds 1,200 kPa (174 psi), the ECM will detect this condition and increase the idle speed by about 50 RPM in order to compensate for the excess load.