DIAGNOSIS AND REPAIR WORK FLOW

Work Flow

OVERALL SEQUENCE

1. Check DTC.
2. Perform the following procedure if DTC is displayed.

• Record DTC and freeze frame data. (Print them out with CONSULT-III or GST.)
• Erase DTC. (Refer to See: Scan Tool Testing and Procedures\On Board Diagnostic (OBD) System\Diagnosis Description.)
• Study the relationship between the cause detected by DTC and the symptom described by the customer. (Symptom Table is useful. Refer to See: Symptom Related Diagnostic Procedures.)

3. Check related service bulletins for information. Are any symptoms described and any DTCs detected?

Symptom is described, DTC is displayed>>GO TO 3.
Symptom is described, DTC is not displayed>>GO TO 4.
Symptom is not described, DTC is displayed>>GO TO 5.
3.CONFIRM THE SYMPTOM
Try to confirm the symptom described by the customer (except MIL ON).
Also study the normal operation and fail-safe related to the symptom. Refer to See: Normal Operating Condition and See: Fail Safe.
Diagnosis Work Sheet is useful to verify the incident.
Verify relation between the symptom and the condition when the symptom is detected.
>> GO TO 5.
4.CONFIRM THE SYMPTOM
Try to confirm the symptom described by the customer.
Also study the normal operation and fail-safe related to the symptom. Refer to See: Normal Operating Condition and See: Fail Safe.
Diagnosis Work Sheet is useful to verify the incident.
Verify relation between the symptom and the condition when the symptom is detected.
>> GO TO 6.
5.PERFORM DTC CONFIRMATION PROCEDURE
Perform DTC CONFIRMATION PROCEDURE for the displayed DTC, and then check that DTC is detected again.
If two or more DTCs are detected, refer to See: A L L Diagnostic Trouble Codes ( DTC )\Testing and Inspection\DTC Priorities for Troubleshooting\ECM and determine trouble diagnosis order.

NOTE:

• Freeze frame data is useful if the DTC is not detected.
• Perform Component Function Check if DTC CONFIRMATION PROCEDURE is not included. This simplified check procedure is an effective alternative though DTC cannot be detected during this check. If the result of Component Function Check is NG, it is the same as the detection of DTC by DTC CONFIRMATION PROCEDURE.

Is DTC detected?
YES >> GO TO 10.
NO >> Check according to See: Testing and Inspection\Initial Inspection and Diagnostic Overview\Service Information For Electrical Incident\Intermittent Incident.
6.PERFORM BASIC Inspection
Perform See: Programming and Relearning\Basic Inspection.
Will CONSULT-III be used?
YES >> GO TO 7.
NO >> GO TO 9.
7.PERFORM "SPEC" OF "DATA MONITOR" MODE
With CONSULT-III
Check that "MAS A/F SE-B1", "B/FUEL SCHDL", "A/F ALPHA-B1" and "A/F ALPHA-B2" are within the SP value using "SPEC" of "DATA MONITOR" mode with CONSULT-III. Refer to See: Scan Tool Testing and Procedures\Trouble Diagnosis - Specification Value\Component Function Check.
Are they within the SP value?
YES >> GO TO 9.
NO >> GO TO 8.
8.DETECT MALFUNCTIONING PART BY TROUBLE DIAGNOSIS - SPECIFICATION VALUE
Detect malfunctioning part according to See: Scan Tool Testing and Procedures\Trouble Diagnosis - Specification Value\Diagnosis Procedure.
Is a malfunctioning part detected?
YES >> GO TO 11.
NO >> GO TO 9.
9.DETECT MALFUNCTIONING SYSTEM BY SYMPTOM TABLE
Detect malfunctioning system according to See: Symptom Related Diagnostic Procedures based on the confirmed symptom in step 4, and determine the trouble diagnosis order based on possible causes and symptoms.
>> GO TO 10.
10.DETECT MALFUNCTIONING PART BY DIAGNOSTIC PROCEDURE
Inspect according to Diagnostic Procedure of the system.

NOTE:
The Diagnostic Procedure in Engine Control System described based on open circuit Inspection. A short circuit Inspection is also required for the circuit check in the Diagnostic Procedure. For details, refer to "Circuit Inspection" in See: Testing and Inspection\Initial Inspection and Diagnostic Overview\Service Information For Electrical Incident\Circuit Inspection.
Is a malfunctioning part detected?
YES >> GO TO 11.
NO >> Monitor input data from related sensors or check voltage of related ECM terminals using CONSULT-III. Refer to See: Pinout Values and Diagnostic Parameters\Reference Value.
11.REPAIR OR REPLACE THE MALFUNCTIONING PART

1. Repair or replace the malfunctioning part.
2. Reconnect parts or connectors disconnected during Diagnostic Procedure again after repair and replacement.
3. Check DTC. If DTC is displayed, erase it, refer to See: Scan Tool Testing and Procedures\On Board Diagnostic (OBD) System\Diagnosis Description. >> GO TO 12.

12.FINAL CHECK
When DTC was detected in step 2, perform DTC CONFIRMATION PROCEDURE or Overall Function Check again, and then check that the malfunction have been completely repaired.
When symptom was described from the customer, refer to confirmed symptom in step 3 or 4, and check that the symptom is not detected.
Is DTC detected and does symptom remain?
YES-1 >> DTC is detected: GO TO 10.
YES-2 >> Symptom remains: GO TO 6.
NO >> Before returning the vehicle to the customer, always erase unnecessary DTC in ECM and TCM
(Transmission Control Module). (Refer to See: Scan Tool Testing and Procedures\On Board Diagnostic (OBD) System\Diagnosis Description.) If the completion of
SRT is needed, drive vehicle under the specific DRIVING PATTERN in See: Programming and Relearning\How To Set SRT Code.