Celica L4-1998cc 2.0L DOHC (3S-GE) (1986)
Compressor Speed Sensor: Technical Service Bulletins
A/C - Compressor Belt Protection System Description
REFERENCE ELECTRICAL
NUMBER 013
DATE
05-16-86
MODEL
AE (FR), ST, SV
CV, CE
CONDITION:
The indicator lamp in the A/C switch begins flashing with the air conditioning switched on in Camry, Celica, Corolla SR5/GT-S, or Diesel Corolla
models.
CAUSE:
A possible cause is that the air conditioner amplifier has sensed a compressor malfunction and/or drive belt slippage, and has disengaged the compressor
magnetic clutch to prevent reduction of alternator or power steering pump output, and/or belt damage.
CORRECTION:
Determine the cause of the compressor malfunction or belt slippage and correct as necessary.
NORMAL SYSTEM OPERATION
NORMAL SYSTEM OPERATION:
The air conditioner compressor is equipped with a revolution sensor. The output of this sensor is compared by the A/C amplifier with engine RPM. If the
amplifier senses a drop in compressor RPM relative to engine RPM it determines that a problem in the compressor has occurred. If this condition
continues for longer than 0.6 seconds, the compressor clutch is switched off, idle up is released, and the A/C switch indicator lamp flashes. The indicator
lamp will continue to flash until the ignition switch is turned off to cancel the flashing light.
See also TSB Volume VII, Electrical Number 020