Flow of Diagnosis
HOW TO PROCEED WITH TROUBLESHOOTING1. CUSTOMER PROBLEM ANALYSIS
Using the customer problem analysis check sheet for reference, ask the customer in as much detail as possible about the problem.
Customer Problem Analysis Check Sheet
2. CHECK AND CLEAR THE diagnostic trouble codes (PRECHECK)
Before confirming the problem symptom, first check the diagnostic trouble code if there are any trouble codes stored in memory. When there are trouble codes, make a note of them, then clear them before proceeding.
HINT: In diagnostic trouble code check, it is very important to determine whether the problem indicated by the diagnostic trouble code is still occurring or occurred in the past but returned to normal at present. In addition, it must be checked in the problem symptom check whether the malfunction indicated by the diagnostic trouble code is directly related to the problem symptom or not. For this reason, the diagnostic trouble codes should be checked before and after the symptom confirmation to determine the current conditions. If this is not done, it may depending on the case, result in unnecessary troubleshooting for normally operating systems, thus making it more difficult to locate the problem, or in repairs not pertinent to the problem. Therefore, always follow the procedure in correct order and perform the diagnostic trouble code check.
Displaying & Reading Trouble Codes
^ Proceed to "3. Problem Symptom Confirmation".
3. PROBLEM SYMPTOM CONFIRMATION
Confirm the problem symptoms.
HINT: Refer to procedures under Procedures / Problem Symptom Confirmation.
Symptom Related Diagnostic Procedures
4. SYMPTOM SIMULATION
If the problem does not reappear, be sure to simulate the problem by checking the circuits indicated by the diagnostic trouble code in step 2., using "Problem Simulation Methods".
5. DIAGNOSTIC TROUBLE CODE CHECK
Check the diagnostic trouble codes. Check if there is abnormality in the sensors or the wire harness.
Displaying & Reading Trouble Codes
^ If a trouble 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 steps 2. and 3. are completed.
HINT: If troubleshooting is attempted only by following the trouble code stored in the memory is output, errors could be made in the diagnosis.
6. DIAGNOSTIC TROUBLE CODE CHART
If a trouble 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 transaxle oil level. throttle cable adjustment, etc.
8. SHIFT POSITION SIGNAL CHECK
Carry out the shift position signal check (TT Terminal Output Voltage Test under Electronic Circuit Tests) when the transaxle gears do not up-shift, down-shift or lock-up. This is to check the output condition from the engine control module (ECM) to each solenoid.
^ If the results are NG, then it is likely that the trouble is in the electrical system (particularly in the sensor 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
Perform Stall Test, Time Lag Test and Line Pressure Test as described under "Procedures/Manual System Tests".
^ If the malfunction is found in the stall test. time lag test or line pressure test, check the parts indicated in the respective tests.
10. MANUAL SHIFTING TEST
Perform manual shifting test as described under "Procedures/Manual System Tests".
Mechanical System Tests
^ 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 0f Problem Symptoms.
11. MATRIX CHART OF PROBLEM SYMPTOMS
If the normal code is confirmed in the diagnostic trouble code check, perform inspection of each circuit or part according to the inspection order in the "Matrix Chart 0f Problem Symptoms".
The Matrix Chart contains 3 sections;
- Part 1: Electronically Controlled Circuits
^ If all the circuits indicated in Part 1 are normal, proceed to Part 2.
- Part 2: On-vehicle Inspection
^ If all the parts indicated in Part 2 are normal, proceed to Part 3.
- Part 3: Off-vehicle Inspection
^ If all the circuits and parts in Part 1 - Part 3 are normal and the trouble still occurs, check and replace the ECM.
Testing and Inspection
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 or brake signal check 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 database or the '94 A246E Automatic Transaxle 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 automatic transaxle is operating correctly.