Flow of Diagnosis

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.
2. CHECK AND CLEAR THE DIAGNOSTIC TROUBLE CODES (PRECHECK)
Before confirming the problem symptom, first check if there are any diagnostic trouble 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".
3. PROBLEM SYMPTOM CONFIRMATION
Confirm the problem symptoms.
4. SYMPTOM SIMULATION
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".
If the normal code is output, proceed to "11. Matrix Chart of Problem Symptoms".
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.
7. PRELIMINARY CHECK
Carry out a preliminary check of the transmission oil level, throttle cable adjustment, etc.
8. SHIFT POSITION SIGNAL CHECK
Carry out the shift position signal check when the transmission gears do not up-shift, down-shift or lock-up. This is to check the 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.
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.
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 chapters, Electronically Controlled Circuits in Chapter 1, On-vehicle Inspection in Chapter 2 and Off-vehicle Inspection in Chapter 3.
If all the circuits indicated in Chapter 1 are normal, proceed to Chapter 2. If all the parts indicated in Chapter 2 are normal. proceed to Chapter 3. If all the circuits and parts in Chapter 1 - Chapter 3 are normal and the trouble still occurs, check and replace the ECM.
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.
13. PARTS INSPECTION
Check the individual parts of the mechanical system and hydraulic system in the order of the numbers indicated in the Matrix Chart.
14. REPAIRS
After the cause of the problem is located, perform repairs by following the inspection and replacement procedures in this manual or A340E, A341E Automatic Transmission Repair Manual.
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 electronically controlled transmission system is operating correctly.