Automatic Transaxle (Diagnostics - Introduction): Other Scion xD I

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

The RESET MEMORY cannot be completed by only disconnecting the battery cable.

Note. The automatic transaxle is composed of high precision 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. As far as possible, complete the inspection, repair and reassembly before proceeding to the next component group. If a defect is found in a certain component group during reassembly, inspect and repair that group immediately. If a component group cannot be assembled because some parts are on order, 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. When changing the automatic transmission fluid, use Toyota Genuine ATF WS or equivalent. 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 cloth. Only recommended ATF 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 brake and clutch discs 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 or similar parts. Make sure that the ends of snap rings are not aligned with any cutouts and are installed in the grooves correctly. When replacing a worn bushing, the sub-assembly containing the bushing must also be replaced. Check thrust bearings and races for wear and 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. 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

Scheme 392

SYSTEM DIAGRAM

The configuration of the electronic control system in the U341E automatic transaxle is as shown in the following chart.

Scheme 393

Scheme 394

Scheme 395

MECHANICAL SYSTEM TESTS

1. 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 a 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 2110 to 2710 RPM EVALUATION: Problem Possible cause 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. 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 a 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 a Techstream to the DLC3. Fully apply the parking brake. Start and warm up the engine and check idle speed. Idle speed Approximately 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 396

1. 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 test must be conducted after checking and adjusting the engine. Perform this test with A/C 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 a Techstream to the DLC3. Start the engine and check idling speed. Keep your left foot pressed 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 91 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 19.0 kgf/cm 2 , 240 to 271 psi) EVALUATION: Problem Possible cause If the measured values at all positions are higher Shift solenoid valve SLT defective Regulator valve defective 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 397

1. 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. OK: Shift Lever Operation L to 2 Shifting does not occur 2 to 3 Shifting does not occur 3 to D Shifting does not occur D to 3 Shifting does not occur 3 to 2 Shifting does not occur 2 to L Shifting does not occur Turn the ignition switch off. Connect the transmission wire connector. Clear DTCs. Refer to «DTC CHECK / CLEAR»(ref-388736-S09090221702011031100000) . HINT: When the transmission wire is disconnected, the transaxle gear will be set as listed below. Shift Lever Gear P Park R Reverse N Neutral D 3rd 3 3rd 2 3rd L 3rd

INITIALIZATION

1. 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 a Techstream. HINT: The ECM memorizes the conditions when the ECT controls the automatic transaxle assembly and engine assembly . 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 a Techstream to the DLC3. Turn the ignition switch to ON. Turn the Techstream 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-388736-S41369419532011031100000) described earlier. HINT: The ECM learns through the ROAD TEST.

Scheme 398

1. 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 to 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 a 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: It is necessary to drive the vehicle for approximately 30 minutes to detect DTC P0711 (ATF temperature sensor malfunction).

FAIL-SAFE CHART

1. 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. Position NORMAL SHIFT SOLENOID S1 MALFUNCTIONING Solenoid valve Gear Solenoid valve Gear S1 S2 S1 S2 D ON ON 1st X ON --> OFF 3rd ON OFF 2nd X OFF 3rd OFF OFF 3rd X OFF 3rd OFF ON 4th X ON 4th 3 ON ON 1st X ON --> OFF 3rd ON OFF 2nd X OFF 3rd OFF OFF 3rd X OFF 3rd 2 ON ON 1st X ON --> OFF 3rd ON OFF 2nd X OFF 3rd L ON ON 1st X ON --> OFF 3rd Position SHIFT SOLENOID S2 MALFUNCTIONING BOTH SOLENOIDS MALFUNCTIONING Solenoid valve Gear Gear when shift selector is manually operated S1 S2 D ON X 2nd 3rd ON X 2nd 3rd OFF X 3rd 3rd OFF X 3rd 3rd 3 ON X 2nd 3rd ON X 2nd 3rd OFF X 3rd 3rd 2 ON X 2nd 3rd ON X 2nd 3rd L ON X 2nd 3rd 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 "-->".