PRECAUTION
Note. Perform the RESET MEMORY (AT initialization) when replacing the automatic transaxle assembly, engine assembly or ECM. Refer to INITIALIZATION . Perform the REGISTRATION (VIN registration) when replacing the ECM. Refer to REGISTRATION
HINT
RESET MEMORY can not be completed by only disconnecting the battery cable.
- EXPRESSIONS OF IGNITION SWITCH The type of ignition switch used on this model differs according to the specifications of the vehicle. The expressions listed in the table below are used in this article. Switch Type Ignition Switch (Position) Engine Switch (Condition) Expression Ignition switch off LOCK Off Ignition switch ON ON On (IG) Ignition switch ACC ACC On (ACC) Engine start START Start
- REMOVAL AND INSTALLATION PROCEDURE PRECAUTIONS The automatic transaxle is composed of highly precision-finished parts which need careful inspection before reassembly. Even a small nick could cause fluid leakage or affect the performance. The instructions here are organized so that you work on only one component group at a time. This will help avoid confusion caused by similar-looking parts of different sub-assemblies being on your workbench at the same time. The component groups are inspected and repaired from the converter housing side. Complete the inspection, repair and reassembly before proceeding to the next component group as much as possible. If a defect is found in a certain component group during reassembly, inspect and repair this group immediately. If a component group cannot be assembled because some parts are being ordered, be sure to keep all parts of the group in a separate container while proceeding with disassembly, inspection, repair and reassembly of other component groups. Recommended: Toyota Genuine ATF WS All disassembled parts should be washed clean and any fluid passages and holes should be blown through with compressed air. Dry all parts with compressed air. Never use a piece of cloth to dry them. When using compressed air, always aim away from yourself to prevent accidentally spraying ATF or kerosene in your face. Only recommended automatic transaxle fluid or kerosene should be used for cleaning. After cleaning, the parts should be arranged in the correct order for efficient inspection, repair, and reassembly. New discs for the brakes and clutches that are to be used for replacement must be soaked in ATF for at least 15 minutes before reassembly. All oil seal rings, clutch discs, clutch plates, rotating parts, and sliding surfaces should be coated with ATF prior to reassembly. All gaskets and rubber O-rings should be replaced with new ones. Do not apply adhesive cements to gaskets and similar parts. Make sure that the ends of a snap ring are not aligned with one of the cutouts and are installed in the groove correctly. When replacing a worn bushing, the sub-assembly containing the bushing must also be replaced. Check thrust bearings and races for wear or damage. Replace them as necessary. When working with FIPG material, you must observe the following: Using a razor blade and a gasket scraper, remove all the old packing (FIPG) material from the gasket surface. Thoroughly clean all components to remove any loose material. Clean both sealing surfaces with a non-residue solvent. Parts must be reassembled within 10 minutes of application. Otherwise, the packing (FIPG) material must be removed and reapplied.
DEFINITION OF TERMS
| Term | Definition |
|---|---|
| Monitor description | Description of what the ECM monitors and how it detects malfunctions (monitoring purpose and its details). |
| Related DTCs | Diagnostic code |
| Typical enabling condition | Preconditions that allow the ECM to detect malfunctions. With all preconditions satisfied, the ECM sets the DTC when the monitored value(s) exceeds the malfunction threshold(s). |
| Sequence of operation | The priority order that is applied to monitoring, if multiple sensors and components are used to detect the malfunction. While another sensor is being monitored, the next sensor or component will not be monitored until the previous monitoring has concluded. |
| Required sensor/components | The sensors and components that are used by the ECM to detect malfunctions. |
| Frequency of operation | The number of times that the ECM checks for malfunctions per driving cycle. "Once per driving cycle" means that the ECM detects malfunction only one time during a single driving cycle. "Continuous" means that the ECM detects malfunction every time when enabling condition is met. |
| Duration | The minimum time that the ECM must sense a continuous deviation in the monitored value(s) before setting a DTC. This timing begins after the "typical enabling conditions" are met. |
| Malfunction thresholds | Beyond this value, the ECM will conclude that there is a malfunction and set a DTC. |
| MIL operation | MIL illumination timing after a defect is detected. "Immediately" means that the ECM illuminates MIL the instant the ECM determines that there is a malfunction. "2 driving cycle" means that the ECM illuminates MIL if the same malfunction is detected again in the 2nd driving cycle. |
| Component operating range | Normal operation range of sensors and solenoids under normal driving conditions. Use these ranges as a reference. They cannot be used to judge if a sensor or solenoid is defective or not. |
Scheme 10
Scheme 11
SYSTEM DIAGRAM
The configuration of the electronic control system in the U341E automatic transaxle is as shown in the following chart.
Scheme 12
MECHANICAL SYSTEM TESTS
- PERFORM MECHANICAL SYSTEM TESTS Measure the stall speed. The object of this test is to check the overall performance of the transaxle and engine by measuring the stall speeds in the D position. NOTE: Driving test should be done on a paved road (a nonskid road). Perform the test at the normal operating ATF (Automatic Transmission Fluid) temperature 50 to 80°C (122 to 176°F). Do not continuously run this test for longer than 5 seconds. To ensure safety, do this test in a wide, clear level area which provides good traction. The stall test should always be carried out in pairs. One technician should observe the conditions of wheels or wheel stoppers outside the vehicle while the other is doing the test. Chock the 4 wheels. Connect the Techstream to the DLC3. Fully apply the parking brake. Keep your left foot pressed firmly on the brake pedal. Start the engine. Shift into the D position. Press all the way down on the accelerator pedal with your right foot. Quickly read the stall speed at this time. Stall speed 2390 +- 300 RPM EVALUATION: Problem Possible cause (a) Stall engine speed is low in D position Engine power output may be insufficient Stator one-way clutch not operating properly HINT: If the value is less than the specified value by 600 RPM or more, the torque converter could be faulty. (b) Stall engine speed is high in D position Line pressure is too low Forward clutch slipping No. 2 one-way clutch not operating properly Improper fluid level Measure the time lag. When the shift lever is shifted while the engine is idling, there will be a certain time lapse or lag before the shock can be felt. This is used for checking the condition of the clutch and brake. NOTE: Perform the test at the normal operating ATF (Automatic Transmission Fluid) temperature: 50 to 80°C (122 to 176°F). Be sure to allow 1 minute interval between tests. Perform the test three times, and measure the time lags. Calculate the average value of the three time lags. Connect the Techstream to the DLC3. Fully apply the parking brake. Start and warm up the engine and check idle speed. Idle speed approx. 700 RPM (In N position and A/C OFF) Shift the lever from N to D position. Using a stop watch, measure the time from when the lever is shifted until the shock is felt. Time lag N --> D less than 1.2 seconds In the same way, measure the time lag for N --> R. Time lag N --> R less than 1.5 seconds EVALUATION (IF N --> D OR N --> R TIME LAG IS LONGER THAN THE SPECIFIED): Problem Possible cause N --> D time lag is longer Line pressure is too low Forward clutch worn No. 2 one-way clutch is not operating properly N --> R time lag is longer Line pressure is too low Reverse clutch worn 1st and reverse brake worn
Scheme 13
- PERFORM HYDRAULIC TEST Measure the line pressure. NOTE: Perform the test at the normal operating ATF (Automatic Transmission Fluid) temperature: 50 to 80°C (122 to 176°F). The line pressure test should always be carried out in pairs. One technician should observe the conditions of wheels or wheel stoppers outside the vehicle while the other is performing the test. Be careful to prevent SST hose from interfering with the exhaust pipe. This Check must be conducted after checking and adjusting engine. Perform under condition that A/C is OFF. When conducting stall test, do not continue more than 5 seconds. Warm up the ATF. Remove the test plug on the front left side of the transaxle case and connect SST. SST: 09992-00095 09992-00231 09992-00271 Fully apply the parking brake and chock the 4 wheels. Connect the Techstream to the DLC3. Start the engine and check idling speed. Keep your left foot pressing firmly on the brake pedal and shift into D position. Measure the line pressure when the engine is idling. Depress the accelerator pedal all the way down. Quickly read the highest line pressure when engine speed reaches stall speed. In the same way, do the test in R position. SPECIFIED LINE PRESSURE: Condition D position kPa (kgf/cm 2 , psi) R position kPa (kgf/cm 2 , psi) Idling 372 to 412 kPa (3.8 to 4.2 kgf/cm 2 , 54 to 60 psi) 553 to 623 kPa (5.6 to 6.4 kgf/cm 2 , 80 to 100 psi) Stall test 1120 to 1230 kPa (11.4 to 12.5 kgf/cm 2 , 162 to 178 psi) 1660 to 1870 kPa (16.9 to 19.1 kgf/cm 2 , 241 to 271 psi) EVALUATION: Problem Possible cause If the measured values at all positions are higher Shift solenoid valve SLT defective Regulator valve detective If the measured values at all positions are lower Shift solenoid valve SLT defective Regulator valve detective Oil pump defective If pressure is low in the D position only D position circuit fluid leak Forward clutch defective If pressure is low in the R position only R position circuit fluid leak Reverse clutch defective 1st and reverse brake defective
Scheme 14
- MANUAL SHIFTING TEST The purpose of this manual shifting test is to determine whether a problem is caused by either mechanical or electrical factors. Disconnecting the transmission wire disables electrically-controlled automatic gear shifting. In this case, operating the shift lever is the only way to shift the transaxle gear. If the gear is not changed by shift lever operation, it is assumed that there is a mechanical problem. Turn the ignition switch off. Disconnect the transmission wire connector. Warm up the engine. Drive the vehicle. Check the transaxle operation when the shift lever is moved into L, 2, 3 and D positions. STANDARD: Shift Lever Operation L to 2 No Shift (Not Change) 2 to 3 No Shift (Not Change) 3 to D No Shift (Not Change) D to 3 No Shift (Not Change) 3 to 2 No Shift (Not Change) 2 to L No Shift (Not Change) Turn the ignition switch off. Connect the transmission wire connector. Clear DTCs. Refer to «DTC CHECK / CLEAR»(ref-425891-S28857405032011101200000) . HINT: When the transmission wire is disconnected, the transaxle gear will be set as listed below. Shift Lever Gear P Parking R Reverse N Neutral D 3rd 3 3rd 2 3rd L 3rd
INITIALIZATION
- RESET MEMORY NOTE: Perform the RESET MEMORY (AT initialization) when replacing the automatic transaxle assembly, engine assembly or ECM. The RESET MEMORY can be performed only with the Techstream. HINT: The ECM memorizes the condition that the ECT controls the automatic transaxle assembly and engine assembly according to those characteristics. Therefore, when the automatic transaxle assembly, engine assembly, or ECM has been replaced, it is necessary to reset the memory so that the ECM can memorize the new information. Reset procedure is as follows. Turn the ignition switch off. Connect the Techstream to the DLC3. Turn the ignition switch to ON and the Techstream main switch on. Enter the following menus: Powertrain / Engine and ECT / Utility / Reset Memory. Then, press "Next". WARNING: After performing the RESET MEMORY, be sure to perform the ROAD TEST. Refer to «ROAD TEST»(ref-425891-S33501504642011101200000) described earlier. HINT: The ECM is learned by performing the ROAD TEST.
Scheme 15
- MONITOR DRIVE PATTERN FOR ECT TEST Perform this drive pattern as one method to simulate the detection conditions of the ECT malfunctions. (The DTCs may not be detected due the actual driving conditions. And some codes may not be detected through this drive pattern.) HINT: Preparation for driving Warm up the engine sufficiently. (Engine coolant temperature is 60°C (140°F) or higher) Drive the vehicle when the atmospheric temperature is -10°C (14°F) or higher. (Malfunction is not detected when the atmospheric temperature is less than -10°C (14°F)) Driving note Drive the vehicle through all gears. Stop --> 1st --> 2nd --> 3rd --> 4th --> 4th (lock-up ON). Repeat the above driving pattern three times or more. NOTE: When using the Techstream, monitor status can be found in the "Powertrain / Engine and ECT / Data List". In the event that the drive pattern must be interrupted (possibly due to traffic conditions or other factors), the drive pattern can be resumed and, in most cases, the monitor can be completed. Perform this drive pattern on a level road as much as possible and strictly observe the posted speed limits and traffic laws while driving. HINT: *1: Drive at such a speed in the uppermost gear, to engage lock-up. The vehicle can be driven at a speed lower than that in the above diagram under the lock-up condition. NOTE: If necessary to drive the vehicle for approximately 30 minutes to detect DTC P0711 (ATF temperature sensor malfunction).
FAIL-SAFE CHART
- FAIL-SAFE This function minimizes the loss of the ECT functions when any malfunction occurs in each sensor or solenoid. Vehicle speed signal (SPD): When there are problems with vehicle speed signals, 4th upshift is prohibited. Input turbine speed sensor NT (Speed sensor NT): When the input turbine speed sensor has a malfunction, 4th upshift is prohibited. ATF (Automatic Transmission Fluid) temperature sensor: When the ATF temperature sensor has a malfunction, 4th upshift is prohibited. Shift solenoid valve SLU: If the ECM detects a malfunction in the solenoid valve SLU, it turns the valve off. Shift solenoid valve SLT: When the solenoid valve SLT has a malfunction, 4th upshift is prohibited. Engine coolant temperature sensor: When the engine coolant temperature sensor has a malfunction, 4th upshift is prohibited. Knock sensor: When the knock sensor has a malfunction, 4th upshift is prohibited. Throttle position sensor: When the throttle position sensor has a malfunction, 4th upshift is prohibited. Shift solenoid valve S1 and S2: Fail safe function: If either of the shift solenoid valve circuits develops an open or short, the ECM turns the other shift solenoid "ON" and "OFF" in order to shift into the gear positions shown in the table below. The ECM also turns the shift solenoid valve ST OFF at the same time. If both solenoids malfunction, hydraulic control cannot be performed electronically and must be done manually. Manual shifting as shown in the following table must be done (In case of a short circuit, the ECM stops sending current to the short circuit solenoid). Even if starting the engine in the fail-safe mode, the gear position remains in the same position. Normal Solenoid Valve S1 ON ON OFF OFF S2 ON OFF OFF ON Gear Position 1st 2nd 3rd 4th (O/D) S1 Malfunction Solenoid Valve S1 X S2 ON --> OFF OFF OFF ON Gear Position *1 3rd 3rd 3rd 4th (O/D) S2 Malfunction Solenoid Valve S1 ON ON OFF OFF S2 X Gear Position *1 2nd 2nd 3rd 3rd S1 and S2 Malfunction Solenoid Valve S1 X S2 X Gear Position *1 3rd 3rd 3rd 3rd *1: Actual gear shift (gear position) under fail-safe operation. X: OFF (the ECM stops sending current to a malfunctioning solenoid valve) -->: Condition in the electrical malfunction is shown on the left of "-->". Condition in the fail-safe mode is shown on the right of "-->".