Flow of Diagnosis

HOW TO PROCEED WITH TROUBLESHOOTING USING VOLT/OHM METER
1. CUSTOMER PROBLEM ANALYSIS
Using the customer problem analysis check sheet for reference, ask the customer in as much detail as possible about the problem. Refer to Preliminary Checks / Customer Problem Analysis Worksheet. Initial Inspection and Diagnostic Overview

2. CHECK AND CLEAR THE DIAGNOSTIC TROUBLE CODES (PRECHECK)
Before confirming the problem symptom, first check the diagnostic trouble code if there are any malfunction codes stored in memory. When there are malfunction codes, make a note of them, then clear them and proceed to 3 Problem Symptom Confirmation". Refer to How to Display and Read Diagnostic Trouble Codes. Initial Inspection and Diagnostic Overview

3. PROBLEM SYMPTOM CONFIRMATION, (4) SYMPTOM SIMULATION
Confirm the problem symptoms. If the problem does not reappear, be sure to simulate the problem by mainly checking the circuits indicated by the diagnostic trouble code in step (2), using "Problem Simulation method".

5. DIAGNOSTIC TROUBLE CODE CHECK
Check the diagnostic trouble codes. Check if there is abnormality in the sensors or the wire harness. If a malfunction code is output proceed to "(6) Diagnostic Trouble Code Chart". Refer to Trouble Code Descriptions. Initial Inspection and Diagnostic Overview

If the normal code is output, proceed to "(7) Matrix Chart of Problem Symptoms". Refer to Diagnosis by Symptom / Matrix Chart of Problem Symptoms. Initial Inspection and Diagnostic Overview

Be sure to proceed to (6) Diagnostic Trouble Code Chart after the steps (2) and (3) are completed.
If troubleshooting is attempted only by following the malfunction code stored in the memory is output, errors could be made in the diagnosis.

6. DIAGNOSTIC TROUBLE CODE CHART
If a malfunction code is confirmed in the diagnostic trouble code check, proceed to the inspection procedure indicated by the matrix chart for each diagnostic trouble code. Refer to Diagnosis by Symptom / Matrix Chart of Problem Symptoms. Initial Inspection and Diagnostic Overview

7. PRELIMINARY CHECK
Carry out a preliminary check of the transmission oil level, throttle cable adjustment, etc. Refer to Preliminary Checks. Initial Inspection and Diagnostic Overview

8. SHIFT POSITION SIGNAL CHECK
Carry out the shift position signal check when the transmission gears do not upshift, downshift, or lockup. This is to check the signal output condition from the ECM to each solenoid. If the results are NG, then it is likely that the trouble is in the electrical system (particularly in the sensors or the ECM). Proceed to Part 1 (Electrical System) under (11) "Matrix Chart of Problem Symptoms". If all the circuits specified in Part 1 are OK, check the ECM and replace it. Refer to Diagnosis by Symptom / Matrix Chart of Problem Symptoms. Initial Inspection and Diagnostic Overview

9. MECHANICAL SYSTEM TEST
(Stall Test, Time Lag Test, Line Pressure Test, Accumulator Back Pressure Test)
If the malfunction is found in the stall test, time lag test, line pressure test or accumulator back pressure test, check the parts indicated in the respective tests. If the problem is that "shift shock is large", perform the accumulator back pressure test.

10. MANUAL SHIFTING TEST
If the results of the manual driving test are NG, it is likely that the trouble is in the mechanical system or hydraulic system. Proceed to Part 2 (Mechanical System) under the Matrix Chart of Problem Symptoms. Refer to Diagnosis by Symptom / Matrix Chart of Problem Symptoms. Initial Inspection and Diagnostic Overview

11. MATRIX CHART OF PROBLEM SYMPTOMS
If the normal code is confirmed in the diagnostic trouble code check, perform inspection according to the inspection order in the matrix chart of problem symptoms. Perform diagnosis of each circuit or part in the order shown in the Matrix Chart. The Matrix Chart contains 3 Section, Electronically Controlled Circuits in Section 1, On-vehicle Inspection in Section 2 and Off-vehicle Inspection in Section 3. If all the circuits indicated in Section 1 are normal, proceed to Section 2. If all the parts indicated in Section 2 are normal, proceed to Section 3. If all the circuits and parts in Section 1 - Section 3 are normal and the trouble still occurs, check and replace the ECM. Refer to Diagnosis by Symptom / Matrix Chart of Problem Symptoms. Initial Inspection and Diagnostic Overview

12. CIRCUIT INSPECTION
Perform diagnosis of each circuit in accordance with the inspection order confirmed in (6) and (11).
Judge whether the cause of the problem is in the sensor, actuators, wire harness and connectors, or the ECM. In some cases, the Flow Chart instructs that a throttle signal check, brake signal check or kick down signal check (in test mode) be performed. These are diagnosis functions used to check if signals are being input correctly to the ECM. Refer to Diagnostic Charts / Trouble Code Charts or Non-Trouble Code Charts. Initial Inspection and Diagnostic Overview

13. PART INSPECTION
Check the individual parts of the mechanical system and hydraulic system in the order of the numbers indicated in the Matrix Chart. Refer to Diagnosis by Symptom / Matrix Chart of Problem Symptoms. Initial Inspection and Diagnostic Overview

14. REPAIRS
After the cause of the problem is located, perform repairs by following the inspection and replacement procedures.

15. CONFIRMATION TEST
After completing repairs, confirm not only that the malfunction is eliminated, but also conduct a test drive etc., to make sure the entire electronic controlled transmission system is operating correctly.