FixVault
Home › Toyota › 2003 › Tundra Base, Automatic › Repair and Diagnosis › Transmission › Automatic Trans › Automatic Transmission - Diagnostics › Pre-Check

Automatic Transmission - Diagnostics: Pre-Check

  1. DIAGNOSIS SYSTEM 
    1. Description
      • When troubleshooting the OBD II vehicles, the only difference from the usual troubleshooting procedure is that you connect the OBD II scan tool complying with SAE J1987 or the hand-held tester to the vehicle, and read off the various data output from the vehicle's ECM.

        The OBD II regulations require that the vehicle's on-board computer should light 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 the vehicle emissions. In addition to the MIL lighting up when a malfunction is detected, the applicable DTCs prescribed by the SAE J2012 are recorded in the ECM memory.

        Fig 1: Identifying Malfunctioning Indicator Lamp
        G02843823Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

        If the malfunction only occurs in 3 trips, the MIL goes off but the DTCs remain recorded in the ECM memory.

      • To check the DTCs, connect the scan tool (OBD II scan tool or hand-held tester) to the DLC3 on the vehicle. The scan tool also enables you to erase the DTCs and check the freeze frame data and various forms of engine data (For further information, refer to the instruction book).
        Fig 2: Connecting Hand-Held Tester To DLC3
        G02843824Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

        • NOTE: 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. Also referred to as 2-trip detection logic.
      • The diagnosis system operates in the normal mode during the normal vehicle use, and also has the check mode for technicians to simulate malfunction symptoms and perform the troubleshooting. Most DTCs use the 2-trip detection logic to prevent erroneous detection. By switching the ECM to the check mode when troubleshooting, the technician can cause the MIL to light up for the malfunction that is only detected once or momentarily (hand-held tester only).
      2. NOTE:

      If the display shows "UNABLE TO CONNECT TO VEHICLE" when you have connected the cable of the scan tool (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 the scan tool side.

      • If the communication is normal when the scan tool is connected to another vehicle, inspect the DLC3 on the original vehicle.
      • If the communication is still impossible when the scan tool is connected to another vehicle, the problem is probably in the scan tool itself, so consult the Service Department listed in the scan tool's instruction manual.
      Fig 3: Identifying DLC3 Connector Terminal
      G02843825Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      Fig 4: Terminals Specified Condition Chart
      G02843826Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Inspect the DLC3.

      The vehicle's ECM uses the V.P.W. (Variable Pulse Width) for communication to comply with the SAE J1850. The terminal arrangement of the DLC3 complies with the SAE J1962 and matches the V.P.W. format.

  2. INSPECT DIAGNOSIS (NORMAL MODE) 
    1. Check the MIL.
      Fig 5: Identifying Malfunction Indicator Lamp
      G02843827Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. The MIL comes on when the ignition switch is turned ON and the engine is not running.
        NOTE:

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

      2. When the engine is started, the MIL should go off. If the lamp remains on, the diagnosis system has detected a malfunction or an abnormality in the system.
      2. NOTE: Hand- held tester only: When the diagnosis system is switched from the normal mode to the check mode, all the DTCs and freeze frame data recorded in the normal mode will be erased. So before switching modes, always check the DTCs and freeze frame data, and make a note.
    2. Check the DTC.
      1. Connect the scan tool (OBD II scan tool or handheld tester) to the DLC3.
        Fig 6: Connecting Handheld Tester To DLC3
        G02843828Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      2. Turn the ignition switch ON and turn the scan tool switch ON.
        3. NOTE: When simulating symptoms with the OBD II scan tool (excluding hand-held tester) to check the DTCs, use the normal mode. For codes on the DTCs chart subject to the "2 trip detection logic", turn the ignition switch off after the symptoms have been simulated the 1st time. Then use the simulation process again.
      3. Use the scan tool to check the DTCs and freeze frame data and make a note (For operating instructions, see the scan tool's instruction book).
      4. See DIAGNOSTIC TROUBLE CODE CHART  to confirm the details of the DTCs.
  3. INSPECT DIAGNOSIS (CHECK MODE) 
      NOTE:

      Hand-held tester only: Compared to the normal mode, the check mode has high sensibility to detect malfunctions. Furthermore, the same diagnostic items which are detected in the normal mode can also be detected in the check mode.

    1. Check the DTC.
      1. Check the initial conditions.
        • Battery positive voltage 11 V or more.
        • Throttle valve fully closed.
        • Transmission in P position.
        • Air conditioning switched off.
      2. Turn the ignition switch OFF.
      3. Connect the hand-held tester to the DLC3.
        Fig 7: Connecting Hand-Held Tester To DLC3
        G02843829Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      4. Turn the ignition switch ON and the hand-held tester ON.
      5. Switch the hand-held tester from the normal mode to the check mode (Check that the MIL flashes).
        Fig 8: Malfunction Indicator Lamp Blinking Pattern
        G02843830Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
        6. NOTE: Leave the ignition switch ON until you have checked the DTCs, etc.
      6. Start the engine (the MIL goes off after the engine starts).
      7. Simulate the conditions of the malfunction described by the customer.
        8. NOTE:

        Take care not to turn the ignition switch OFF, because it switches the diagnosis system from the check mode to the normal mode and erases all the DTCs, etc.

      8. After simulating the malfunction conditions, use the hand-held tester diagnosis selector to check the DTCs and freeze frame data, etc.
      9. After checking the DTC, inspect the applicable circuit.
    2. Clear the DTC.

      Operate the scan tool (OBD II scan tool or hand-held tester) to erase the DTC and freeze frame data (See the scan tool's instruction book for the operating instructions.).

  4. ROAD TEST 
    NOTE: Conduct the test at the normal operating temperature of the ATF: 50 - 80°C (122 - 176°F).
    1. D position test:

      Shift into the D position and fully depress the accelerator pedal to check the following points.

      1. Check the up-shift operation.

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

        NOTE:
        • O/D Gear Up-shift Prohibition Control (1. Coolant temperature is 60°C (140°F) or less. 2. There is a 10 km/h (6 mph) difference between the set speed of the cruise control and the actual 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 abnormal shock and slip at the up-shifts.
      3. Check for abnormal noises and vibration.

        Drive in the D position lock-up and the O/D gear to check for abnormal noises and vibration.

        NOTE:

        The cause of abnormal noises and vibration must be checked very thoroughly, because they could also cause loss of balance in the differential or torque converter clutch, etc.

      4. Check the kick-down operation.

        While driving in the D position, 2nd, 3rd and O/D gears, check if the 2 --> 1, 3 --> 2, and O/D --> 3 kick-downs take place and if the shift points conform to the automatic shift schedule (See SERVICE DATA ).

      5. Check for abnormal shock and slip at the kick-downs.
      6. Check the lock-up mechanism.
        • Drive in the D position, O/D gear, at a steady speed (lock-up ON) of about 70 km/h (43 mph).
        • Lightly depress the accelerator pedal and check that the engine speed does not change abruptly.

      If there is a big jump in the engine speed, there is no lock-up.

    2. 2 position test:

      Shift into the 2 position and fully depress the accelerator pedal to check the following points.

        NOTE:

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

      1. Check the up-shift operation.

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

      2. Check the engine braking.

        While driving 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 abnormal shock at the up-shift and the down-shift.

    3. L position test:

      Shift into the L position and fully depress the accelerator pedal to check the following points.

      1. Check that there is no up-shift.

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

      2. Check the engine braking.

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

      3. Check for abnormal noises during acceleration and deceleration.

      4. WARNING: Before conducting this test, ensure that the test area is free from people and obstruction.
    4. R position test:

      Shift into the R position and fully depress the accelerator pedal and check for slipping.

    5. P position test:

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

  5. BASIC INSPECTION 
      NOTE:
      • Drive the vehicle until the engine and transmission become the normal operating temperature.

        ATF temperature: 70 - 80°C (158 - 176°F) 

      • Only use the COOL range on the dipstick as a rough reference when the ATF is replaced or the engine does not run.
      Fig 9: Checking ATF Level Using Dipstick
      G02843831Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      NOTE: Do not overfill.
    1. Check the ATF level.
      1. Park the vehicle on a level surface and set the parking brake.
      2. With the engine idling and the brake pedal depressed, shift the shift lever into all positions from P to L and put it back to the P position.
      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 range, add new ATF.

      ATF: T-IV 

    2. Check the ATF condition.

      If the ATF smells burnt or the color is black, replace it.

    3. Replace the ATF.
      1. Remove the drain plug and drain the ATF.
        Fig 10: Removing Drain Plug
        G02843832Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      2. Reinstall the drain plug securely.
      3. With the engine OFF, add new ATF through the oil filler pipe.
        Fig 11: Identifying Engine Oil Level And Adding ATF Through Oil Filler Pipe
        G02843833Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

        ATF: T-IV 

        Capacity: 2.2 liters (2.3 US qts, 2.0 Imp. qts) 

      4. Start the engine and shift the shift lever into all positions from P to L, and then put it back to the P position.
        5. CAUTION: Do not overfill.
        Fig 12: Checking ATF Level Using Dipstick
        G02843834Courtesy 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 - 80°C (158 - 176°F), and add as necessary.
    4. Check the fluid leaks.

      If there are leaks, it is necessary to repair or replace the O-rings, the FIPGs, the oil seals, the plugs or the other parts.

    5. Inspect and adjust the shift lever position.

      When shifting the shift lever from the N position to the other positions, check that the lever can be shifted smoothly and accurately to each position and that the position indicator correctly indicates the position.

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

      1. Loosen the nut on the control shaft lever.
        Fig 13: Loosening Nut On Control Shaft Lever
        G02843835Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      2. Push the control shaft fully rearward.
      3. Return the control shaft lever by 2 notches.
      4. Set the shift lever to the N position.
      5. While holding the shift lever lightly toward the R position, adjust the control lever nut.
      6. Tighten the control shaft lever nut.

        Torque: 12.5 N.m (130 kgf.cm, 9 ft.lbf) 

    6. Inspect and adjust the park/neutral position.

      If the engine does not start at the P and N positions, carry out the following adjustment procedure.

      1. Loosen the park/neutral position switch bolt and set the shift lever to the N position.
        Fig 14: Loosening Park/Neutral Position Switch Bolt
        G02843836Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      2. Align the groove with the neutral basic line.
      3. Tighten the bolt at the position.

        Torque: 13 N.m (130 kgf.cm, 10 ft.lbf) 

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

    7. Check the idle speed.

      Connect the OBD II scan tool or the hand-held tester to the DLC3 and inspect the idle speed.

      Fig 15: Connecting Hand-Held Tester To DLC3
      G02843837Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Idle speed: 700 +/- 50 rpm (In the N position and air conditioner OFF) 

  6. MECHANICAL SYSTEM TESTS 
      CAUTION:
      • Conduct the test at the normal operating temperature of the ATF: 50 - 80°C (122 - 176°F).
      • Do not run this test continuously for more than 5 seconds.
      • To ensure safety, conduct this test in a wide, clear and level area which provides good traction.
      • The test should always be carried out in pairs. One technician should observe the conditions of the wheels or the wheel stoppers outside the vehicle while the other is conducting the test.
      Fig 16: Stall Speed - Problem Symptom Chart
      G02843838Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Check the stall speed.

      The object of this test is to check the overall performance of the transmission and engine by measuring the stall speed in the D and R positions.

      1. Chock the 4 wheels.
      2. Connect the scan tool (OBD II scan tool or hand-held tester) to the DLC3.
      3. Fully apply the parking brake.
      4. Keep your left foot depressing firmly the brake pedal.
      5. Start the engine.
      6. Shift into the D position. Depress all the way down the accelerator pedal with your right foot. Quickly read the stall speed at this time.

        Stall speed: 2,250 +/- 150 rpm 

      7. Conduct the same test in the R position.

        Stall speed: 2,250 +/- 150 rpm 

      Evaluation: 

      2. CAUTION:
      • Conduct the test at the normal operating temperature of the ATF: 50 - 80°C (122 - 176°F).
      • Be sure to allow 1 minute interval between the tests.
      • Perform measurement 3 times and take the average value.
      Fig 17: Time Lag - Problem Symptom Chart
      G02843839Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the time lag.

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

      1. Fully apply the parking brake.
      2. Start the engine and check the idle speed.

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

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

        Time lag at N --> D: Less than 1.2 seconds 

      4. In the same manner, measure the time lag at N --> R.

        Time lag at N --> R: Less than 1.5 seconds 

      Evaluation (if the N --> D or N --> R is longer than the specified): 

    7. CAUTION:
    • Conduct the test at the normal operating temperature of the ATF: 50 - 80°C (122 - 176°F).
    • The line pressure test should always be carried out in pairs. One technician should observe the conditions of the wheels or the wheel stoppers outside the vehicle while the other is conducting the test.
    • Be careful to prevent the SST's hose from interfering with the exhaust pipe.
    Fig 18: Evaluation - Problem Symptom Chart
    G02843840Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  7. HYDRAULIC TEST 

    Measure the line pressure.

    1. Warm up the ATF.
    2. Remove the test plug on front left side of the transmission case front left side and connect the SST (See 3.4L - Fig 2 or 4.7L - Fig 16 in REMOVAL & INSTALLATION article for graphics showing the location to connect SST).

      SST 09992-00095 (09992-00151, 09992-00271)

    3. Fully apply the parking brake and chock the 4 wheels.
    4. Start the engine and check the idle speed.
    5. Keep your left foot depressing firmly the brake pedal and shift the shift lever into the D position.
    6. Measure the line pressure while the engine is idling.
    7. Depress the accelerator pedal all the way down. Quickly read the highest line pressure when the engine speed reaches the specified stall speed (in the mechanical system tests).
    8. In the same manner, conduct the test in the R position.

    Specified line pressure (5VZ-FE): 

    LINE PRESSURE SPECIFICATION (5VZ-FE)

    Condition D position kPa (kgf/cm2 , psi) R position kPa (kgf/cm2 , psi)
    Idling 380 - 440 (3.9 - 4.5,51 - 64) 600-695 (6.1 - 7.1, 87 - 101)
    Stall 1,090 - 1,225 (11.1 - 12.5, 158 - 178) 1,460- 1,795 (14.9- 18.3, 212 - 260)

    Specified line pressure (2UZ-FE): 

    LINE PRESSURE SPECIFICATION (2UZ-FE)

    Condition D position kPa (kgf/cm2 , psi) R position kPa (kgf/cm2 , psi)
    Idling 480 -540 (4.9- 5.5, 70 - 78) 695 - 795 (7.1 - 81, 101 - 115)
    Stall 1,360 - 1, 500 (13.9 - 15.3, 197-218) 1,735 - 2,070 (17.7- 21 1, 252 - 300)

    If the measured pressures are not up to the specified values, recheck the throttle cable adjustment and re-test.

    Evaluation 

    8. NOTE:

    By this test, it can be determined if the trouble is within the electrical circuit or if there is a mechanical problem in the transmission.

  8. MANUAL SHIFTING TEST 
    1. Disconnect the solenoid wire.
      Fig 19: Disconnecting Solenoid Wire
      G02843841Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Inspect the manual driving operation.

      Check that the shift and gear positions correspond to GEAR POSITION .

      GEAR POSITION

      Shift Position Gear Position
      D O/D
      2 3rd
      L 1st
      R Reverse
      P Pawl Lock
      NOTE:

      If the L, 2 and D positions and the gear positions are difficult to be distinguished, conduct the manual shifting test. While driving, shift the shift lever through the L, 2 and D positions. Check that the changed gear corresponds to the shift position.

      If any abnormality is found during the manual shifting test, the problem is in the transmission itself.

    3. Connect the solenoid wire.
    4. Clear the DTC.
About FixVault