DIAGNOSIS AND REPAIR WORKFLOW
Trouble Diagnosis Flow Chart

Trouble Diagnosis Procedure
INTERVIEW WITH CUSTOMER Interview with the customer is important to detect the root cause of CAN communication system errors and to understand vehicle condition and symptoms for proper trouble diagnosis.
Points in interview
NOTE:
- Example: Circuit between ECM and the combination meter is judged normal if the customer indicates tachometer functions normally.
Indication of the combination meter is important to detect the root cause because it is the most obvious to the customer, and it performs CAN communication with many units.

INSPECTION OF VEHICLE CONDITION Check whether the symptom is reproduced or not.
NOTE: Do not turn the ignition switch OFF or disconnect the battery cable while reproducing the error. The error may temporarily correct itself, making it difficult to determine the root cause.
CHECK OF CAN SYSTEM TYPE (HOW TO USE CAN SYSTEM TYPE SPECIFICATION CHART) Determine CAN system type based on vehicle equipment.
NOTE:
CAN System Type Specification Chart (Style A)
NOTE:
CAN system type is easily checked with the vehicle equipment identification information shown in the chart.

CAN System Type Specification Chart (Style B)
NOTE:
CAN system type is easily checked with the vehicle equipment identification information shown in the chart.

CREATE INTERVIEW SHEET
Fill out the symptom described by the customer, vehicle condition, and CAN system type on the interview sheet.
Interview Sheet (Example)

DETECT THE ROOT CAUSE CAN diagnosis function of CONSULT detects the root cause.
Trouble diagnosis
How to use this manualU121D AV control unit
DTC Logic
Diagnosis Procedure
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
...
Audio system
System Diagram
System Description
AUDIO SYSTEM
The audio system consists of the following components
AV control unit
Display unit
BOSE speaker amp.
Window antenna
Steering wheel audio control switches
A/C and AV switch assembly
Front door speakers
Tweeters
Center speaker
...
Low tire pressure warning
If the vehicle is being driven with low tire
pressure, the warning light will illuminate.
A "Tire Pressure Low - Add Air" warning
also appears in the vehicle information display.
When the low tire pressure warning light
illuminates, you should stop and adjust the
tire pressure of all four ...