Pinout Values and Diagnostic Parameters

AIR CONDITIONING: AIR CONDITIONING SYSTEM: TERMINALS OF ECU

TERMINALS OF ECU

1. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY
(a) Disconnect the connector from the air conditioning amplifier assembly.
(b) Measure the voltage and resistance according to the value(s) in the table below.









If the results are not as specified, inspect the circuits connected to the other parts.
(c) Connect the connector to the air conditioning amplifier assembly.
(d) Measure the voltage and resistance according to the value(s) in the table below.





















(1) Waveform 1:
Measure the waveform between terminals A7-9 (BLC) and A7-12 (GND).
OK:
A waveform should be output as shown in the illustration.
HINT: Waveform cycle varies with the blower level.





(2) Waveform 2:
Measure the waveform between terminals A7-9 (BLC) and A7-12 (GND).
OK:
A waveform should be output as shown in the illustration.
HINT: As vehicle speed increases, the cycle of the signal waveform becomes narrow.