Automatic Transmission (Diagnostics): Pre-Check

1. Description
   • When troubleshooting On-Board Diagnostic (OBD II) vehicles, the vehicle must be connected to the OBD II scan tool (in compliance with SAE J1978) or the hand-held tester. Various data output from the vehicle's ECM can then be read.
   • OBD II regulations require that the vehicle's onboard computer lights up the Malfunction Indicator Lamp (MIL) on the instrument panel when the computer detects a malfunction in the computer itself or in the drive system components which affect vehicle emissions. In addition to the MIL lighting up when a malfunction is detected, the applicable DTCs prescribed by SAE J2012 are recorded in the ECM memory (See DIAGNOSTIC TROUBLE CODE CHART ).

     If a malfunction only occurs in 3-trip, the MIL turns off but the DTCs remain recorded in the ECM memory.

     Fig 1: Identifying Malfunction Indicator Lamp

     Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   • To check the DTCs, connect the OBD II scan tool or hand-held tester to the DLC3 on the vehicle. The OBD II scan tool or hand-held tester also enables you to erase the DTCs and check freeze frame data and various forms of engine data*. (* See the tester's instruction book for further details).
   • DTCs include SAE controlled codes and Manufacturer controlled codes.

     SAE controlled codes must be set as prescribed by the SAE, while Manufacturer controlled codes can be set freely by the manufacturer within the prescribed limits (see the DTC chart on DIAGNOSTIC TROUBLE CODE CHART ).

     Fig 2: Connecting OBD II Scan Tool Or Hand-Held Tester To DLC3

     Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   • The diagnosis system operates in normal mode during normal vehicle use, and also has a check mode for technicians to simulate malfunction symptoms and perform troubleshooting. Most DTCs use 2-trip detection logic(*) to prevent erroneous detection. By switching the ECM to check mode when troubleshooting, a technician can cause the MIL to light up for a malfunction that is only detected once or momentarily (hand- held tester) (See PRE-CHECK ).
   • *2-trip detection logic: When a logic malfunction is first detected, the malfunction is temporarily stored in the ECM memory. If the same malfunction is detected again during the 2nd test drive, this 2nd detection causes the MIL to light up.
2. Inspect the DLC3.

   The vehicle's ECM uses ISO 9141-2 for communication. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 9141-2 format.

   Fig 3: Identifying DLC3 Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT:

If your display shows "UNABLE TO CONNECT TO VEHICLE" when you have connected the cable of the OBD II scan tool or hand-held tester to the DLC3, turned the ignition switch ON and operated the scan tool, there is a problem on the vehicle side or tool side.

• If communication is normal when the tool is connected to another vehicle, inspect the DLC3 on the original vehicle.
• If communication is still not possible when the tool is connected to another vehicle, the problem is probably in the tool itself, so consult the Service Department listed in the tool's instruction manual.

1. Check the MIL.
   1. The MIL turns on when the ignition switch is turned ON and the engine is not running.

      HINT:

      If the MIL does not light up, troubleshoot the combination meter (See TROUBLESHOOTING ).

   2. When the engine is started, the MIL should turn off. If the lamp remains on, the diagnosis system has detected a malfunction or abnormality in the system.
      Fig 4: Checking MIL

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Check for DTCs.
   NOTE: Hand-held tester only: When the diagnostic system is switched from normal mode to check mode, all DTCs and freeze frame data recorded in normal mode will be erased. Before switching modes, always check for DTCs and freeze frame data, and write them down.
   NOTE:

   1. Prepare an OBD II scan tool (complying with SAE J1978) or hand-held tester.
   2. Connect the OBD II scan tool or hand-held tester to the DLC3 in the lower part of the instrument panel.
   3. Turn the ignition switch ON and turn the OBD II scan tool or hand-held tester switch ON.
   4. Use the OBD II scan tool or hand-held tester to check for DTCs and freeze frame data and write them down (for operating instructions, see the OBD II scan tool's instruction book).
   5. See DIAGNOSTIC TROUBLE CODE CHART  to confirm the details of the DTCs.

   
   When simulating symptoms with the OBD II scan tool (excluding hand-held tester) to check the DTCs, use normal mode. For codes on the DTCs chart subject to "2-trip detection logic", turn the ignition switch OFF after the symptoms have been simulated the 1st time. Then repeat the simulation process again. When the program has DTCs they are recorded in the ECM.
   Fig 5: Connecting OBD II Scan Tool Or Hand-Held Tester To DLC3

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT:

Hand-held tester only:

Compared to the normal mode, the check mode has high sensing ability to detect malfunctions. Furthermore, the same diagnostic items which are detected in normal mode can also be detected in check mode.

1. Check the DTC.
   1. Check the initial conditions.
      • Battery positive voltage 11 V or more
      • Throttle valve fully closed
      • Transaxle in P position
      • Air conditioning switched OFF
   2. Turn the ignition switch OFF
   3. Prepare a hand-held tester
   4. Connect the hand-held tester to the DLC3 in the lower part of the instrument panel.
   5. Turn the ignition switch ON and switch the hand-held tester ON.
      Fig 6: Connecting Hand-Held Tester To DLC3 In Lower Part Of Instrument Panel

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   6. Switch the hand-held tester from normal mode to check mode (check that the MIL flashes).
   7. Start the engine (MIL turns off after the engine starts).
   8. Simulate the conditions of the malfunction described by the customer.
      NOTE: Leave the ignition switch ON until you have checked the DTCs, etc..
   9. After simulating the malfunction conditions, use the hand-held tester diagnosis selector to check for DTCs and freeze frame data, etc.
      Fig 7: Checking MIL Flashes

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT:

      Take care not to turn the ignition switch OFF. If the ignition switch is turned off, the diagnosis system is switched from check mode to normal mode, which erases all DTCs, etc.

   10. After checking the DTC, inspect the applicable circuit.
2. Clear the DTC.

   Operating the OBD II scan tool (complying with SAE J1978) or hand-held tester can erase the DTC and freeze frame data. (See the OBD II scan tool's instruction book for operating instructions).

This reference list indicates the part name used in this manual along with their definitions.

Fig 9: Toyota/Lexus Part And System Name List (1 Of 2)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 10: Toyota/Lexus Part And System Name List (2 Of 2)

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HINT:

This table indicates ECM monitoring status for the items in the upper columns if the DTCs in each line on the left are being set.

As for the "X" mark, when the DTC on the left is stored, detection of the DTC in the upper column is not performed.

Fig 11: Monitor Malfunction Detection & Disablement List (1 Of 4)

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Fig 12: Monitor Malfunction Detection & Disablement List (2 Of 4)

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Fig 13: Monitor Malfunction Detection & Disablement List (3 Of 4)

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Fig 14: Monitor Malfunction Detection & Disablement List (4 Of 4)

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Taking the results of the customer problem analysis into consideration, try to reproduce the symptoms of the problem. If the problem is that the transaxle does not up-shift or down-shift, or the shift point is too high or too low, conduct the following road test to confirm the automatic shift schedule and simulate the problem symptoms.

1. D position test

   Move the shift lever into the D position, fully depress the accelerator pedal and check the following points:

   1. Check up-shift operation.

      Check to see that 1 --> 2, 2 --> 3 and 3 --> O/D up-shifts take place, and that the shift points conform to the automatic shift schedule (see SERVICE DATA ).

      HINT:

      • O/D Gear Up-shift Prohibition Control (1. Coolant temperature, is 60 °C (140 °F) or less. 2. If there is a 10 km/h (6 mph) difference between the set cruise control speed and vehicle speed.)
      • O/D Gear Lock-up Prohibition Control (1. Brake pedal is depressed. 2. Coolant temperature is 60 °C (140 °F) or less.)
   2. Check for shift shock and slip.

      Check for shock and slip at the 1 --> 2, 2 --> 3 and 3 --> O/D up-shifts.

   3. Check for abnormal noises and vibration.

      Run the vehicle at the D position lock-up or O/D gear and check for abnormal noises and vibration.

      HINT:

      The check for the cause of abnormal noises and vibration must be done very thoroughly as it could also be due to loss of balance in the differential torque converter clutch, etc.

   4. Check kick-down operation.

      While running the vehicle in the D position, 2nd, 3rd and O/D gears, check to see that the possible kick-down vehicle speed limits for 2 --> 1,3 --> 2 and O/D --> 3 kick-downs conform to those indicated in the automatic shift schedule (see SERVICE DATA ).

   5. Check abnormal shock and slip at kick-down.
   6. Check the lock-up mechanism.
      • Drive the vehicle in the D position and O/D gear at a steady speed (lock-up ON) of about 60 km/h (37 mph).
      • Lightly depress the accelerator pedal and check that the engine speed does not change abruptly.

   If engine speed changes abruptly, there is no lock-up.

2. position test

   Move the shift lever into the 2 position, fully depress the accelerator pedal and check the following points:

   1. Check up-shift operation.

      Check to see that the 1 --> 2 up-shift takes place and that the shift point conforms to the automatic shift schedule (see SERVICE DATA ).

      HINT:

      There is no O/D up-shift and lock-up in the 2 position.

   2. Check engine braking.

      While running the vehicle in the 2 position and 2nd gear, release the accelerator pedal and check the engine braking effect.

   3. Check for abnormal noises during acceleration and deceleration, and for shock at up-shift and down-shift.
3. L position test

   Move the shift lever into the L position, fully depress the accelerator pedal and check the following points:

   1. Check no up-shift.

      While running the vehicle in the L position, check that there is no up-shift to the 2nd gear.

   2. Check engine braking.

      While running the vehicle in the L position, release the accelerator pedal and check the engine braking effect.

   3. Check for abnormal noises during acceleration and deceleration.
4. R position test

   Move the shift lever into the R position, fully depress the accelerator pedal and check for slipping.

   CAUTION: Before conducting this test ensure that the test area is free from people and obstruction.
5. P position test

   Stop the vehicle on a grade (more than 5°) and move the shift lever into the P position, release the parking brake. Then, check to see that the parking lock pawl holds the vehicle in place.

1. Check the fluid level.

   HINT:

   • Drive the vehicle so that the engine and transaxle are at normal operating temperature.

     Fluid temperature: 70 to 80 °C (158 to 176 °F) 

   • Only use the COOL range on the dipstick as a rough reference when the fluid is replaced or the engine does not run.
   1. Park the vehicle in a flat area and set the parking brake.
   2. With the engine idling and the brake pedal depressed, move the shift lever into all positions from the P to L position and return it to the P position.
      Fig 15: Identifying Column Shifting And Floor Shifting

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   3. Pull out the dipstick and wipe it clean.
   4. Push it back fully into the pipe.
   5. Pull it out and check that the fluid level is in the HOT range.

   If the level is not within the hot range, add new fluid.

   Fluid type: ATF D-II or DEXRON®III (DEXRON®II) 

   Fig 16: Checking Fluid Level

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   NOTE:

   • Do not overfill.
   • After filling ATF, check the oil level securely then drive a vehicle.
2. Check the fluid condition.

   If the fluid smells burnt or is black, replace it.

3. Replace the ATF.
   1. Remove the drain plug and drain the fluid.
   2. Reinstall the drain plug securely.
      Fig 17: Identifying Drain Plug

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   3. With the engine OFF, add new fluid through the oil filler pipe.

      Fluid type: ATF D-II or DEXRON®III (DEXRON®II) 

      Capacity: 4.75 liters (5.0 US qts, 4.2 lmp. qts) 

   4. Start the engine and move the shift lever into all positions from the P to L position and then shift it into the P position.
      Fig 18: Adding New Fluid Through Oil Filler Pipe

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   5. With the engine idling, check the fluid level. Add fluid up to the COOL level on the dipstick.
   6. Check the fluid level at the normal operating temperature, 70 to 80 °C (158 to 176 °F), and add as necessary.
   NOTE: Do not overfill.
4. Check the fluid leaks.

   Check for leaks in the transaxle.

   Fig 19: Checking Fluid Level

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   If there are leaks, repair or replace O-rings, gasket, oil seals, plugs or other related parts.

5. Inspect and adjust the throttle cable.
   1. Check that the accelerator pedal is fully released.
   2. Check that the inner cable is not slack.
   3. Measure the distance between the outer cable end and stopper on the cable.

   Standard distance: 0 to 1 mm (0 to 0.04 in.) 

   If the distance is not within the standard, adjust the cable by adjusting the nuts.

   Fig 20: Inspecting And Adjusting Throttle Cable

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
6. Inspect and adjust the shift lever position.

   When shifting the shift lever from the N position to other positions, check that the lever can be shifted smoothly and accurately to each position and that the position indicator is aligned with the correct position.

   If the indicator is not aligned with the correct position, carry out the following adjustment procedures.

   1. Loosen the nut on the shift lever.
      Fig 21: Inspecting And Adjusting Shift Lever Position

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   2. Push the control shaft fully downward.
   3. Return the control shaft lever 2 notches to the N position.
   4. Set the shift lever to the N position.
   5. While holding the shift lever lightly toward the R position side, tighten the shift lever nut.

      Torque: 13 N.m (130 kgf.cm, 9 ft.lbf) 

   6. Start the engine. Make sure that the vehicle moves forward when the lever is shifted from the N to D position and reverses when shifted to the R position.
      Fig 22: Pushing Control Shaft Fully Downward

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
7. Inspect and adjust the park/neutral position.

   Check that the engine can be started with the shift lever only in the N or P position, but not in other positions.

   If it is not as stated above, carry out the following adjustment procedures.

   1. Loosen the park/neutral position switch bolts and set the shift lever to the N position.
   2. Align the groove and neutral basic line.
   3. Hold the park/neutral position switch in position and tighten the bolt.
      Fig 23: Inspecting And Adjusting Park/Neutral Position

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Torque: 5.4 N.m (55 kgf.cm, 48 in.lbf) 

   For continuity check of the park/neutral position switch, see DTC P0705 TRANSMISSION RANGE SENSOR CIRCUIT MALFUNCTION (PRNDL INPUT), DTC P0850 PARK/NEUTRAL SWITCH INPUT CIRCUIT .

8. Check the idle speed.

   Idle speed: 700 +/- 50 rpm 

   (Shift lever in N position and air conditioner OFF) 

1. Measure the stall speed.

   This test checks the overall performance of the transaxle and engine by measuring the stall speeds in the D and R positions.

   NOTE:

   • Conduct the test at normal operating fluid temperature 50 to 80 °C (122 to 176 °F).
   • Do not continuously run this test for longer than 5 seconds.
   • To ensure safety, conduct this test in a wide, clear flat 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.
   1. Chock the 4 wheels.
   2. Connect the OBD II scan tool or the hand-held tester to the DLC3.
   3. Fully apply the parking brake.
   4. Keep your left foot pressing firmly on the brake pedal.
   5. Start the engine.
   6. 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: 2,450 to 2,750 rpm 

   7. Conduct the same test in the R position.

      Stall speed: 2,450 to 2,750 rpm 

   Evaluation: 

   PROBLEM SYMPTOMS TABLE - STALL SPEED
   
   

   Problem	Possible cause
   (c) Stall speed low in D and R positions	Engine output may be insufficient Stator one-way clutch is operating properly HINT: If more than 600 rpm below the specified value, the torque converter clutch could be faulty.
   (d) Stall speed high in D position	Line pressure too low Forward clutch slipping No. 2 one-way clutch not operating properly O/D clutch slipping
   (e) Stall speed high in R position	Line pressure too low Direct clutch slipping 1st & reverse brake slipping O/D clutch slipping
   (f) Stall speed high in D and R positions	Line pressure too low Improper fluid level O/D one-way clutch not operating properly

2. Measure the time lag.

   When the shift lever is moved while the engine is idling, there will be a certain amount of time lapse or lag before shock can be felt. This is used for checking the conditions of the O/D direct clutch, forward clutch, and 1st & reverse brake.

   NOTE:

   • Conduct the test at normal operating fluid temperature 50 to 80 °C (122 to 176 °F).
   • Be sure to allow 1 minute interval between tests.
   • Take 3 measurements and take the average value.
   1. Connect the OBD II scan tool or hand-held tester to the DLC3.
   2. Fully apply the parking brake.
   3. Start the engine and check idle speed.

      Idle speed: 700 +/- 50 rpm (Shift lever in N position and air conditioner OFF) 

   4. Shift the shift lever from the N to D position. Using a stop watch, measure the amount of time from when the lever is shifted until shock is felt.

      N --> D time lag: Less than 1.2 seconds 

   5. Measure the time lag for N --> R using the same procedures as mentioned above (1) to (4).

      N --> R time lag: Less than 1.5 seconds 

   Evaluation (If N --> D time or N --> R time lag is longer than the specified): 

   Fig 24: Problem Symptom Table (Time Lag)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Measure the line pressure.

1. Warm up the ATF.
2. Remove the test plug on the transaxle case front left side and connect SST (see COMPONENTS for the location to connect SST).

   SST 09992-00095 (09992-00231, 09992-00271)

3. Fully apply the parking brake and chock the 4 wheels.
4. Connect the OBD II scan tool or hand-held tester to the DLC3.
5. Start the engine and check idling speed.
6. Keep your left foot pressing firmly on the brake pedal and shift into the D position.
7. Measure the line pressure when the engine is idling.
8. Depress the accelerator pedal all the way down. Quickly read the highest line pressure when engine speed reaches stall speed.
9. Conduct the same test in the R position.

Specified line pressure: 

If the measured pressure is not as specified, recheck the throttle cable adjustment and retest.

Evaluation: 

HINT:

With this test, whether the tansaxle has an electrical problem or a mechanical problem can be determined.

1. Disconnect the solenoid wire.
2. Inspect the manual driving operation.

   Check that the shift and gear positions correspond with the table below.

   While driving, shift the shift lever through the L, 2 and D positions. Check that the gear change corresponds to the shift position.

   Fig 25: Disconnecting Solenoid Wire

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   SHIFT POSITION AND GEAR POSITION
   
   

   Shift Position	Gear Position
   D	O/D
   2	O/D
   L	1st
   R	Reverse
   P	Pawl Lock

   HINT:

   If the L, 2 and D position and gear positions are difficult to position and also to distinguish, conduct the above road test again. If any abnormality is found in the above test, the problem is in the transaxle itself.

3. Connect the solenoid wire.
4. Erase the DTC (See PRE-CHECK ).

HINT:

The ECM memorizes the condition that the ECT controls the automatic transaxle assembly and engine assembly according to those characteristics. Therefore, after the automatic transaxle assembly, engine assembly or ECM has been replaced, it is necessary to reset the memory so that the ECM can memorize new information.

Reset procedure is as follows.

1. Turn the ignition switch off.
2. Connect the hand-held tester to the DLC3.
3. Turn the ignition switch to the ON position and push the hand-held tester main switch on.
4. Select the item "DIAGNOSIS/ENHANCED OBD II".
5. Perform the reset memory procedure from the ENGINE menu.

Fig 26: Tester Menu Flow Chart

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