Pinout Values and Diagnostic Parameters

HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM: TERMINALS OF ECU

TERMINALS OF ECU

1. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY





(a) Disconnect the E36, E35 and z34 air conditioning amplifier connectors.
(b) Measure the voltage and resistance according to the value(s) in the table below.





- If the result is not as specified, there may be a malfunction on the wire harness side.

(c) Reconnect the E36, E35 and z34 air conditioning amplifier connectors.
(d) Measure the voltage according to the value(s) in the table below.













- If the result is not as specified, the air conditioning amplifier assembly may have a malfunction.





(e) Using an oscilloscope, check waveform 1.





HINT: When the rear blower level is increased, the duty ratio changes accordingly.





(f) Using an oscilloscope, check waveform 2.





HINT: When the blower level is increased, the duty ratio changes accordingly.





(g) Using an oscilloscope, check waveform 3.





HINT: When the rear blower level is increased, the duty ratio changes accordingly.

2. CHECK AIR CONDITIONING CONTROL ASSEMBLY (w/o Multi-display)





(a) Disconnect the F10 air conditioning control assembly connector.
(b) Measure the resistance and voltage according to the value(s) in the table below.





- If the result is not as specified, there may be a malfunction on the wire harness side.

(c) Reconnect the F10 air conditioning control assembly connector.
(d) Measure the resistance and voltage according to the value(s) in the table below.





- If the result is not as specified, the air conditioning control assembly may have a malfunction.

3. CHECK MULTI-DISPLAY (w/ Multi-display)





(a) Disconnect the F28 multi-display connector.
(b) Measure the resistance and voltage according to the value(s) in the table below.





- If the result is not as specified, there may be a malfunction on the wire harness side.

(c) Reconnect the F28 multi-display connector.
(d) Measure the resistance and voltage according to the value(s) in the table below.





- If the result is not as specified, the multi-display may have a malfunction.

4. CHECK NO. 2 AIR CONDITIONING CONTROL ASSEMBLY





(a) Disconnect the E55 switch connector.
(b) Measure the resistance and voltage according to the value(s) in the table below.





If the result is not as specified, there may be a malfunction on the wire harness side.
5. CHECK MAIN BODY ECU (COWL SIDE JUNCTION BLOCK LH)





(a) Disconnect the 2A, 2B, 2D and E3 ECU connectors.
(b) Measure the voltage and resistance according to the value(s) in the table below.





If the result is not as specified, there may be a malfunction in the wire harness.