HVAC Control Module and its Circuits Inspection: Automatic A/C
HVAC Control Module and Its Circuits InspectionCAUTION: HVAC control module can not be checked by itself.
It is strictly prohibited to connect voltmeter to HVAC control module with couplers disconnected from it.
HVAC control module and its circuits can be checked at HVAC control module wiring couplers by measuring voltage.
Voltage Check
1. Remove HVAC control module. Refer to HVAC Control Module Removal and Installation.
2. Connect HVAC control module and body control module couplers to HVAC control module and body control module.
3. Check each terminal voltage with couplers connected by referring to HVAC Control Module
Terminal arrangement of HVAC control module (viewed from harness side)
Ter. G52-1 - G52-5:
Ter. G52-6 - G52-18:
Ter. G52-19 - G52-29:
Ter. G52-30:
HVAC Control Module Voltage Table
Reference Waveform No. 1
Waveform at 0 degrees C (32 degrees F)
Waveform at 40 degrees C (104 degrees F)
Waveform at 80 degrees C (176 degrees F)
Reference Waveform No. 2
NOTE: The shape of waveform varies with outside air temperature.
Waveform at 20 degrees C ( 4 degrees F)
Waveform at 0 degrees C (32 degrees F)
Waveform at 30 degrees C (86 degrees F)
Reference Graph