Automatic Transmission - Diagnostics: Pre-Check

DIAGNOSIS SYSTEM

Description
- When troubleshooting OBD II vehicles, the only difference from the usual troubleshooting procedure is that you connect to the vehicle an OBD II scan tool complying with SAE J1987 or hand-held tester, and read off various data output from the vehicle's ECM.
  
  Fig 1: Identifying MIL
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
- OBD II regulations require that the vehicle's on-board computer lights up the Malfunction Indicator Lamp (MIL) on the instrument panel when the computer detects a malfunction in the computer itself or in 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 DEFINITIONS ).
  If the malfunction only occurs in 3-trip, the MIL goes off but the DTCs remain recorded in the ECM memory.
- To check the DTCS, connect an OBD II scan tool or hand-held tester to 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 (For instruction book).
- 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 DIAGNOSTIC TROUBLE CODE CHART ).
- 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, the technician can cause the MIL to light up and 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.

Inspect the DLC3.

Fig 3: Identifying DLC3 Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

The vehicle's ECM uses ISO 9141-2 for communication.

The terminal arrangement of DLC3 complies with SAE J1962 and matches the ISO 9141-2 format.

DLC3 TESTER CONNECTION SPECIFIED VOLTAGE

Tester Connection	Condition	Specified Condition
7 (Bus + Line) - 5 (Signal Ground)	During Communication	Pulse Generation
4 (Chassis Ground) - Body	Always	1 W or less
5 (Signal Ground) - Body	Always	1 W Or Less
16 (B+) - Body	Always	9 - 14 V

NOTE: If your display shows "UNABLE TO CONNECT TO VEHICLE" when you have connected the cable of OBD II scan tool or hand-held tester to 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 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.

INSPECT DIAGNOSIS (NORMAL MODE)

Fig 4: Identifying MIL
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. Check the MIL.
  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 PROBLEM SYMPTOMS TABLE ).
  2. When the engine is started, the MIL should go off. If the lamp remains on, the diagnosis system has detected a malfunction or abnormality in the system.
2. Check the DTC.
  NOTE: Hand-held tester only:
  When the diagnostic system is switched from normal mode to check mode, it erases all DTCs and freeze frame data recorded in normal mode. So before switching modes, always check the DTCs and freeze frame data, and note them down.
  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 DLC3 at the lower 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 the DTCs and freeze frame data and note 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.
    NOTE: When simulating symptoms with an 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.
INSPECT DIAGNOSIS (CHECK MODE)
NOTE: 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 DLC3 at the lower of the instrument panel.
  5. Turn the ignition switch ON and switch the hand-held tester ON.
  6. Switch the hand-held tester from Normal mode to Check mode (Check that the MIL flashes).
  7. Start the engine (MIL goes out 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 the DTCs and freeze frame data, etc.
    NOTE: Take care not to turn the ignition switch OFF, as turning it off switches the diagnosis system from Check mode to Normal mode, so all DTCs, etc. are erased.
  10. After checking the DTC, inspect the applicable circuit.
2. Clearance the DTC.
  The following operation will erase the DTC and freeze frame data. Operating an OBD II scan tool (complying with SAE J1978) or hand-held tester to erase the codes (See the OBD II scan tool's instruction book for operating instructions.).
ROAD TEST
NOTE: Perform the test at normal operating ATF temperature 50 - 80°C (122 - 176°F).
1. D position test
  Shift into the D position and 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-shift takes place, and that the shift points conform the automatic shift schedule (See SERVICE DATA ).
    NOTE:
    O/D Gear Upshift Prohibition Control (1. Coolant temp. 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 temp. 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 at the D position lock-up or O/D gear and check for abnormal noises and vibration.
    
    NOTE: 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 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 in D position, 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 there is a big jump in engine speed, there is no lock-up.
2. 2 position test
  Shift into the 2 position and 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 ).
    
    NOTE: There is no O/D up-shift and lock-up in the 2 position.
  2. Check engine braking.
    While running 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
  Shift into the 2 position and fully depress the accelerator pedal and check the following points:
  1. Check no up-shift.
    While running in the L position, check that there is no up-shift to 2nd gear.
  2. Check engine braking.
    While running 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
  Shift into the R position and 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 after shifting into the P position, release the parking brake. Then, check to see that the parking lock pawl holds the vehicle in place.
BASIC INSPECTION
1. Check the fluid level.
  NOTE:
  - Drive the vehicle so that the engine and transaxle are at normal operating temperature.
    Fluid temp.: 70 - 80°C (158 - 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 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 position and return to P position.
    
    Fig 9: Identifying ATF Fluid Level On Dipstick
    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 range, add new fluid.
    
    Fluid type: ATF D-II or DEXRON®III (DEXRON®II)
    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.
  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 Imp. qts)
  4. Start the engine and shift the shift lever into all positions from P to L position and then shift into P position.
  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.
    NOTE:
    Do not overfill.
4. Check the fluid leaks.
  Check for leaks in the transaxle.
  
  If there are leaks, it is necessary to repair or replace O-rings, gasket, oil seals, plugs or other parts.
5. Inspect and adjust the throttle cable.
  
  Fig 12: Adjusting Throttle Cable
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  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 - 1 mm (0 - 0.04 in.)
    
    If the distance is not the standard, adjust the cable by adjusting nuts.
6. Inspect and adjust the shift lever position.
  
  Fig 13: Identifying Shift Lever Nut
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  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.
  2. Push the control shaft fully downward.
  3. Return the control shaft lever 2 notches to N position.
  4. Set the shift lever to 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 and make sure that the vehicle moves forward when shifting the lever from the N to D position and reverses when shifting it to the R position.
7. Inspect and adjust the park/neutral position.
  
  Fig 15: Locating Neutral Basic Line
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  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 bolt and set the shift lever to the N position.
  2. Align the groove and neutral basic line.
  3. Hold in position and tighten the bolt.
    Torque: 5.4 N.m (55 kgf.cm, 48 in.lbf)
    
    For continuity inspection 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
  
  (In N position and air conditioner OFF)
MECHANICAL SYSTEM TESTS
1. 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 and R positions.
  NOTE:
  - Do the test at normal operating fluid temperature 50 - 80°C (122 - 176°F).
  - Do not continuously run this test longer than 5 seconds.
  - To ensure safety, conduct 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.
  1. Chock the 4 wheels.
  2. Connect an OBD II scan tool or hand-held tester to 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: 2,325 - 2,775 RPM
  7. Do the same test in R position.
    Stall speed: 2,325 - 2,775 RPM
    
    Fig 16: Problem Possible Cause Chart
    Courtesy 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 time lapse or lag before the shock can be felt. This is used for checking the conditions of the O/D direct clutch, forward clutch, and 1st & reverse brake.
  NOTE:
  - Do the test at normal operating fluid temperature 50 - 80°C (122 - 176°F).
  - Be sure to allow 1 minute interval between tests.
  - Take 3 measurements and take the average value.
  1. Connect an OBD II scan tool or hand-held tester to DLC3.
  2. Fully apply the parking brake.
  3. Start the engine and check idle speed.
    Idle speed: 700 +/- 50 RPM (In N position and air conditioner OFF)
  4. Shift the shift 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 manner, measure the time lag for N --> R.
    
    Time lag: N --> R Less than 1.5 seconds
    
    Fig 17: Troubleshooting Chart (If N --> D Time Or N --> R Time Lag Is Longer Than Specified)
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HYDRAULIC TEST

Measure the line pressure.

NOTE:

Do the test at normal operation fluid temperature 50 - 80°C (122 - 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 doing the test.
Be careful to prevent SST's hose from interfering with the exhaust pipe.

Warm up the ATF.
Remove the test plug on the transaxle case front left side and connect SST (See TRANSAXLE for the location to connect SST).
SST 09992-00095 (09992-00231, 09992-00271)
Fully apply the parking brake and chock the 4 wheels.
Connect an OBD II scan tool or hand-held tester to 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 manner, do the test in R position.

SPECIFIED LINE PRESSURE

Condition	D Position kPa (kgf/cm² , psi)	R Position kPa (kgf/cm² , psi)
Idling	401 - 461 (4.1 - 4.7, 58 - 66)	804 - 882 (8.2 - 9.0, 117 - 128)
Stall	1,138 - 1,236 (11.6 - 12.6, 165 - 179)	1,716 - 1,854 (17.5 - 18.9, 249 - 269)

If the measured pressure is not up to the specified value, recheck the throttle cable adjustment and retest.

Fig 18: Problem Possible Cause Chart

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 19: Locating Solenoid Wire

MANUAL SHIFTING TEST

NOTE: With this test, it can be determined whether the trouble is within the electrical circuit or is a mechanical problem in the transaxle.

Disconnect the solenoid wire.

Inspect the manual driving operation.

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

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

SHIFT AND GEAR POSITIONS

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

NOTE: If the L, 2 and D position gear positions are difficult to positions are difficult to distinguish, do the above read test.

If any abnormality is found in the above test, the problem is in the transaxle itself.

Connect the solenoid wire.
Cancel out the DTC (See PRE-CHECK ).