Diagnosis Procedure

1.CHECK AIR MIX DOOR MOTOR (DRIVER SIDE) POWER SUPPLY

Change the power supply mode of the electric motor switch to ON (READY indicator: ON).
Check voltage between air mix door motor (driver side) harness connector and A/C amp. harness connector.

+		−		Voltage
Air mix door motor (driver side)		A/C amp.
Connector	Terminal	Connector	Terminal
M140	1	M54	1	10.5 – 16 V

Is the inspection result normal?

2.CHECK AIR MIX DOOR MOTOR (DRIVER SIDE) GROUND CIRCUIT FOR OPEN

Turn the electric motor switch OFF.
Disconnect air mix door motor (driver side) connector and A/C amp. connector.
Check continuity between air mix door motor (driver side) harness connector and A/C amp. harness connector.
Air mix door motor (driver side) A/C amp. Continuity
Connector Terminal Connector Terminal
M140 2 M54 27 Existed

Air mix door motor (driver side)	A/C amp.	Continuity
M140	2	M54	27	Existed

Is the inspection result normal?

Repair harness or connector.

3.CHECK AIR MIX DOOR MOTOR (DRIVER SIDE) LIN SIGNAL CIRCUIT

Connect air mix door motor (driver side) connector and A/C amp. connector.
Change the power supply mode of the electric motor switch to ON (READY indicator: ON).
Confirm output waveform between air mix door motor (driver side) harness connector and A/C amp. harness connector with oscilloscope.
+ − Output waveform
Air mix door motor (driver side) A/C amp.
Connector Terminal Connector Terminal
M140 3 M54 2

+	−	Output waveform
M140	3	M54	2

Is the inspection result normal?

4.CHECK INSTALLATION OF AIR MIX DOOR MOTOR (DRIVER SIDE)

Check air mix door motor (driver side) is properly installed. Refer to Removal and Installation

Is the inspection result normal?

Replace air mix door motor (driver side). Refer to Removal and Installation

Repair or replace malfunctioning part.

5.CHECK AIR MIX DOOR MOTOR (DRIVER SIDE) POWER SUPPLY CIRCUIT FOR OPEN

Turn the electric motor switch OFF.
Disconnect air mix door motor (driver side) connector and A/C amp. connector.
Check continuity between air mix door motor (driver side) harness connector and A/C amp. harness connector.
Air mix door motor (driver side) A/C amp. Continuity
Connector Terminal Connector Terminal
M140 1 M54 1 Existed

Air mix door motor (driver side)	A/C amp.	Continuity
M140	1	M54	1	Existed

Is the inspection result normal?

Replace A/C amp. Refer to Removal and Installation

Repair harness or connector.

6.CHECK AIR MIX DOOR MOTOR (DRIVER SIDE) LIN SIGNAL CIRCUIT FOR OPEN

Turn the electric motor switch OFF.
Disconnect air mix door motor (driver side) connector and A/C amp. connector.
Check continuity between air mix door motor (driver side) harness connector and A/C amp. harness connector.
Air mix door motor (driver side) A/C amp. Continuity
Connector Terminal Connector Terminal
M140 3 M54 2 Existed

Air mix door motor (driver side)	A/C amp.	Continuity
M140	3	M54	2	Existed

Is the inspection result normal?

Replace A/C amp. Refer to Removal and Installation

Repair harness or connector.