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 manualP0138, P0158 HO2S2
Description
The heated oxygen sensor 2, after three way catalyst (manifold),
monitors the oxygen level in the exhaust gas on each bank.
Even if switching characteristics of the air fuel ratio (A/F) sensor 1
are shifted, the air-fuel ratio is controlled to stoichiometric, by the signal
...
Trouble diagnosis
Condition of Error Detection
DTC (e.g. U1000 and U1001) of CAN communication is indicated on SELF-DIAG
RESULTS on CONSULT if a
CAN communication signal is not transmitted or received between units for 2
seconds or more.
CAN COMMUNICATION SYSTEM ERROR
CAN communication line open (CAN-H, ...
U0415 Vehicle speed sig
Description
U0415 is displayed if any unusual condition is present in the reception
status of the vehicle speed signal from
the ABS actuator and electric unit (control unit).
DTC Logic
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1. DTC CONFIRMATION
Erase the DTC.
Turn ignition ...