Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Detail Of Trouble Diagnosis Flow Chart
- 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
- What: Parts name, system name
- When: Date, Frequency
- Where: Road condition, Place
- In what condition: Driving condition/environment
- Result: Symptom
Notes for checking error symptoms:
- Check normal units as well as error symptoms.
- Example: Circuit between ECM and the combination meter is judged normal if the customer indicates tachometer functions normally.
- When a CAN communication system error is present, multiple control units may malfunction or go into fail-safe mode.
- 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.
GO TO 2.
- INSPECTION OF VEHICLE CONDITION
Check whether the symptom is reproduced or not.
NOTE: Do not turn the ignition switch OFF or disconnect the 12V battery cable while reproducing the error. The error may temporarily correct itself, making it difficult to determine the root cause.GO TO 3.
- CHECK OF CAN SYSTEM TYPE (HOW TO USE CAN SYSTEM TYPE SPECIFICATION CHART)
Determine CAN system type based on vehicle equipment.
NOTE:- This chart is used if CONSULT does not automatically recognize CAN system type.
- There are two styles for CAN system type specification charts. Depending on the number of available system types, either style A or style B may be used.
- 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.
GO TO 4.
- CREATE INTERVIEW SHEET
Fill out the symptom described by the customer, vehicle condition, and CAN system type on the interview sheet.
NOTE: Interview Sheet (Example)GO TO 5.
- DETECT THE ROOT CAUSE
CAN diagnosis function of CONSULT detects a root cause.
GO TO 6.
- REPAIR OR REPLACE MALFUNCTIONING PART
Repair or replace malfunctioning parts identified by CAN diagnosis function of CONSULT.
Vehicle CAN communication circuit
Refer to Vehicle CAN Communication Circuit .
ITS communication circuit
Refer to ITS Communication Circuit .
IT CAN communication circuit
Refer to. IT CAN Communication Circuit
Diagnostic CAN communication circuit
Refer to. Diagnostic CAN Communication Circuit
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.