Diagnosis Procedure
1.CHECK CONNECTOR
Turn the ignition switch OFF.
Disconnect the battery cable from the negative terminal.
Check the terminals and connectors of the data link connector for damage, bend and loose connection (connector side and harness side).
2.CHECK HARNESS FOR OPEN CIRCUIT
Check the resistance between the data link connector terminals.

BCM branch line circuit
M&A branch line circuitPower supply and ground circuit
Diagnosis Procedure
1. CHECK FUSE AND FUSIBLE LINK
Check if the following BCM fuses or fusible link are blown
2. CHECK POWER SUPPLY CIRCUIT
Turn ignition switch OFF.
Disconnect BCM.
Check voltage between BCM harness connector and ground.
3. CHECK GROUND CIRCUIT
Check continuit ...
Power supply and ground circuit
A/C AUTO AMP.
A/C AUTO AMP.: Description
COMPONENT DESCRIPTION
A/C Auto Amp. (Air Conditioner Automatic Amplifier)
The A/C auto amp. (1) has a built-in microcomputer that processes
information sent from various sensors needed for air conditioner
operation. The air mix door motor(s), the mode d ...
U121D AV control unit
DTC Logic
Diagnosis Pro
1.CHECK PLAYBACK OF A DISK (CD)
U121E AV CONTROL UNIT
DTC Logic
Diagnosis Procedure
1.CHECK PLAYBACK OF A DISK (CD)
U1225 AV CONTROL UNIT
DTC Logic
DTC DETECTION LOGIC
...