Work Flow

DIAGNOSIS AND REPAIR WORK FLOW


Work Flow


INTRODUCTION
The TCM receives a signal from the output speed sensor, accelerator pedal position sensor (throttle position sensor) or transmission range switch. Then provides shift control or lock-up control via A/T solenoid valves.





The TCM also communicates with the ECM by means of a signal transmitted from sensing elements used with the OBD-related parts of the A/T system for malfunction-diagnostic purposes. The TCM is capable of diagnosing malfunctioning parts while the ECM can store malfunctions in its memory.
Input and output signals must always be correct and stable in the operation of the A/T system. The A/T system must be in good operating condition and be free of valve seizure, solenoid valve malfunction, etc.





It is much more difficult to diagnose an error that occurs intermittently rather than continuously. Most intermittent errors are caused by poor electric connections or improper wiring. In this case, careful checking of suspected circuits may help prevent the replacement of good parts.
A visual check may not find the cause of the errors. A road test with
CONSULT-III (or GST) or a circuit tester connected should be performed. Follow the "DETAILED FLOW".





Before undertaking actual checks, take a few minutes to talk with the customer who has the driveability complaint. The customer can supply good information about such errors, especially intermittent ones.
Find out what symptoms are present and under what conditions they occur. A "Diagnostic work sheet" as shown in the example (Refer to Diagnostic Work Sheet) should be used.
Start your diagnosis by looking for "conventional" errors first. This will help troubleshoot driveability errors on an electronically controlled engine vehicle.
Also check related Service bulletins.

DETAILED FLOW
1.COLLECT THE INFORMATION FROM THE CUSTOMER
Get the detailed information from the customer about the symptom (the condition and the environment when the incident/malfunction occurred) using diagnosis worksheet. Refer to Diagnostic Work Sheet.
- GO TO 2.
2.CHECK SYMPTOM 1
Check the following items based on the information obtained from the customer.
- Fail-safe. Refer to TCM.
- A/T fluid leakage.
- Stall test. Refer to Stall Test.
- Line pressure test. Refer to Line Pressure Test.
- GO TO 3.
3.CHECK DTC
1. Check DTC.
2. Perform the following procedure if DTC is detected.
- Record DTC.
- Erase DTC. Refer to On Board Diagnostic (OBD) System.
Is any DTC detected?
YES - GO TO 4.
NO - GO TO 6.
4.PERFORM DIAGNOSTIC PROCEDURE
Perform "Diagnosis Procedure" for the displayed DTC.
- GO TO 5.
5.PERFORM DTC CONFIRMATION PROCEDURE
Perform "DTC CONFIRMATION PROCEDURE" for the displayed DTC.
Is any DTC detected?
YES - GO TO 4.
NO - GO TO 6.
6.CHECK SYMPTOM 2
Try to confirm the symptom described by the customer.
Is any malfunction present?
YES - GO TO 7.
NO - INSPECTION END
7.ROAD TEST
Perform "ROAD TEST". Refer to Description.
- GO TO 8.
8.CHECK SYMPTOM 3
Try to confirm the symptom described by the customer.
Is any malfunction present?
YES - GO TO 2.
NO - INSPECTION END