Home/Scion/xB/Scion xB I (2003-2007)/Repair manual/Automatic Trans/Electronic Controlled Automatic Transaxle (ECT): Diagnosis
Contents Wiring diagrams Section: Automatic Trans All sections

Electronic Controlled Automatic Transaxle (ECT): Diagnosis Scion xB I

Automatic Trans 39 illustrations ~4466 words

HOW TO PROCEED WITH TROUBLESHOOTING

The hand-held tester can be used at step 3 , 4 , 6 and 9 .

  1. Vehicle Brought to Workshop
  2. Customer Problem Analysis (See «CUSTOMER PROBLEM ANALYSIS CHECK»(ref-224522-S04190171772006031000000) )
  3. Connect the OBD II scan tool or hand-held tester to DLC3
  4. Check and Clear DTC and Freeze Frame Data (See «DTC CHECK/CLEAR»(ref-224522-S31461245432006031000000) )
  5. Visual Inspection
  6. Setting the Check Mode Diagnosis (See «CHECK MODE PROCEDURE»(ref-224522-S02005169832006031000000) )
  7. Problem Symptom Confirmation (See «ROAD TEST»(ref-224522-S21605981582006031000000) ) Symptom does not occur: Go to step 8 Symptom occur: Go to step 9
  8. Symptom Simulation (See «HOW TO PROCEED WITH TROUBLESHOOTING»(ref-224507-S22289556672006031000000) )
  9. DTC Check (See «DTC CHECK/CLEAR»(ref-224522-S31461245432006031000000) ) DTC is not output: Go to step 10 DTC is output: Go to step 18
  10. Basic Inspection (See «ON-VEHICLE INSPECTION»(ref-224554-S35343821542006031000000), «ADJUSTMENT»(ref-224554-S05016803812006031000000) and «ADJUSTMENT»(ref-224554-S04429166692006031000000) ) NG: Go to step 20 OK: GO TO NEXT STEP
  11. Mechanical System Test (See «MECHANICAL SYSTEM TESTS»(ref-224522-S32752624012006031000000) ) NG: Go to step 17 OK: GO TO NEXT STEP
  12. Hydraulic Test (See «HYDRAULIC TEST»(ref-224522-S42781177912006031000000) ) NG: Go to step 17 OK: GO TO NEXT STEP
  13. Manual Shifting Test (See «MANUAL SHIFTING TEST»(ref-224522-S05665393932006031000000) ) NG: Go to step 15 OK: GO TO NEXT STEP
  14. Problem Symptoms Table Chapter 1 (Scheme 78) NG: Go to step 19 OK: GO TO NEXT STEP
  15. Problem Symptoms Table Chapter 2 (Scheme 79) NG: Go to step 17 OK: GO TO NEXT STEP
  16. Problem Symptoms Table Chapter 3 (Scheme 80) NG: GO TO NEXT STEP
  17. Part Inspection Go to step 20
  18. DTC Chart (See «DIAGNOSTIC TROUBLE CODE CHART»(ref-224522-S36880948192006031000000) )
  19. Circuit Inspection
  20. Identification of Problem
  21. Repair
  22. Confirmation Test End

Scheme 61

Scheme 61: CUSTOMER PROBLEM ANALYSIS CHECK

Scheme 62

Scheme 62: LOCATION

Scheme 63

Scheme 63: DIAGNOSIS SYSTEM

Scheme 64

Scheme 64
  1. Description When troubleshooting OBD II vehicles, the only difference from the usual troubleshooting procedure is that you need to connect an OBD II scan tool complying with SAE J1987 or a hand-held tester to the vehicle, and read off various data output from the vehicle's ECM. OBD II regulations require that the vehicle's onboard computer illuminate 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 illuminating when a malfunction is detected, the applicable DTCs prescribed by SAE J2012 are recorded in the ECM memory (See «DIAGNOSTIC TROUBLE CODE CHART»(ref-224522-S36880948192006031000000) ). If the malfunction does not occur in 3 consecutive trips, the MIL goes off but the DTCs remain in the ECM memory. To check the DTCs, connect the OBD II scan tool or hand-held tester to the DLC3 of 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 operating instructions, see the instruction book.) The 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 a manufacturer within the prescribed limits (See «DIAGNOSTIC TROUBLE CODE CHART»(ref-224522-S36880948192006031000000) ). The diagnosis system operates in the normal mode during the 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 the check mode when troubleshooting, the technician can cause the MIL to illuminate for a malfunction that is only detected once or momentarily, (hand-held tester). *2 trip detection logic: When a malfunction is first detected, the malfunction is temporarily stored in the ECM memory. If the same malfunction is detected again during the second test drive, this second detection causes the MIL to illuminate.
  2. Inspect the DLC3. 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 RESISTANCE SPECIFICATIONS Tester connection Condition Specified condition 7 (Bus + Line) - 5 (Signal ground) During communication Pulse generation 4 (Chassis Ground) - Body Always 1 ohm or less 5 (Signal Ground) - Body Always 1 ohm or less 16 (B+) - Body Always 9 to 14 V 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 to the ON position and operated the scan tool, there is a problem on the vehicle side or tool side. If the communication is normal when the tool is connected to another vehicle, inspect the DLC3 on the original vehicle. If the communication is still impossible 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.
  3. Measure the battery voltage. Battery Voltage: 11 to 14 V If voltage is below 11 V, recharge the battery before proceeding.
  4. Check the MIL. The MIL comes on when the ignition switch is turned to the ON position and the engine is not running. HINT: If the MIL does not light up, troubleshoot the combination meter. When the engine is started, the MIL should go off. If the lamp remains on, it means that the diagnosis system has detected a malfunction or abnormality in the system.

Scheme 65

Scheme 65: DTC CHECK/CLEAR
  1. DTC CHECK (NORMAL MODE) NOTE: Hand-held tester only: When the diagnostic 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 note them down. Checking DTCs using the OBD II scan tool or hand-held tester. Turn the ignition switch off. Connect the OBD II scan tool or hand-held tester to DLC3. Turn the ignition switch to the ON position. 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). See «DIAGNOSTIC TROUBLE CODE CHART»(ref-224522-S36880948192006031000000) 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 the normal mode. For codes on the DTCs chart subject to "2 trip detection logic", turn the ignition switch off after the symptom is simulated once. Then repeat the simulation process again. When the problem has been simulated twice, the MIL is indicated on the instrument panel and DTCs are recorded in the ECM.
  2. DTC CLEAR When using the OBD II scan tool or hand-held tester: Clearing the DTCs. Connect the OBD II scan tool or hand-held tester to the DLC3. Turn the ignition switch to the ON position. When operating the OBD II scan tool (complying with SAE J1978) or hand-held tester to erase the codes, the DTCs and freeze frame data will be erased. (See the OBD II scan tool's instruction book for operating instructions.) When not using the OBD II scan tool or hand-held tester: Clearing the DTCs. Disconnecting the battery terminal or remove the EFI and ETCS fuses from the engine room J/B for 60 seconds or more.

Scheme 66

Scheme 66: CHECK MODE PROCEDURE

Scheme 67

Scheme 67
  1. DTC CHECK (CHECK MODE) HINT: Hand-held tester only: Compared to the normal mode, the check mode has more sensing ability to detect malfunctions. Furthermore, the same diagnostic items which are detected in the normal mode can also be detected in the check mode. Procedure for Check Mode using the hand-held tester. Check the initial conditions. Battery positive voltage 11 V or more Throttle valve fully closed Transaxle in the P or N position A/C switch is off Turn the ignition switch off. Connect the hand-held tester to the DLC3. Turn the ignition switch to the ON position. Switch the hand-held tester from the normal mode to the check mode (Check that the MIL flashes). NOTE: If the hand-held tester switches the ECM from the normal mode to the check mode or vice-versa, or if the ignition switch is turned from the ON position to the ACC or LOCK position during the check mode, the DTC and freeze frame data will be erased. Start the engine (MIL goes off after the engine starts). Simulate the conditions of the malfunction described by the customer. NOTE: Leave the ignition switch in the ON position until you have checked the DTCs, etc. After simulating malfunction conditions, use the hand-held tester diagnosis selector to check the DTCs and freeze frame data, etc. HINT: Be sure not to turn the ignition switch off, as turning it off switches the diagnosis system from the check mode to the normal mode, which erases all the DTCs, etc. After checking the DTC, inspect the applicable circuit.
  2. DTC CLEAR When using the OBD II scan tool or hand-held tester: Clearing the DTCs. Connect the OBD II scan tool or hand-held tester to the DLC3. Turn the ignition switch to the ON position. When operating the OBD II scan tool (complying with SAE J1978) or hand-held tester to erase the codes, the DTCs and freeze frame data will be erased. (See the OBD II scan tool's instruction book for operating instructions.) When not using the OBD II scan tool or hand-held tester: Clearing the DTCs. Disconnecting the battery terminal or remove the EFI and ETCS fuses from the engine room J/B for 60 seconds or more.

ROAD TEST

  1. PROBLEM SYMPTOM CONFIRMATION Taking into consideration the results of the customer problem analysis, try to reproduce the symptoms of the trouble. If the problem is that the transaxle does not shift up, shift down, or the shift point is too high or too low conduct the following road test referring to the automatic shift schedule and simulate the problem symptoms.
  2. PERFORM ROAD TEST NOTE: Conduct the test at normal operating ATF temperature 50 to 80°C (122 to 176°F). D position test Shift into the D position and fully depress the accelerator pedal and check the following points: Check up-shift operation. Check that 1 -> 2, 2 -> 3 and 3 -> O/D up-shift takes place, and that the shift points conform to the automatic shift schedule (See «SERVICE DATA»(ref-224514-S16661207362006031000000) ). HINT: O/D Gear Up-shift Prohibition Control Coolant temp. is 60°C (140°F) or less. ATF temp. is 10°C (50°F) or less. O/D and 3rd Gear Lock-up Prohibition Control Brake pedal is depressed. Accelerator pedal is released. Coolant temp. is 60°C (140°F) or less. ATF temp. is 10°C (50°F) or less. 3rd Gear Lock-up Prohibition Control O/D main switch off (O/D ON) Check for shift shock and slip. Check for shock and slip at the 1 -> 2, 2 -> 3 and 3 -> O/D up-shift. Check for abnormal noises and vibration. Run in 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 sure to loss of balance in the differential, torque converter, etc. Check kick-down operation. Check that the possible kick-down vehicle speed limits for 2nd to 1st, 3rd to 2nd, O/D to 3rd kick-downs conform to those indicated on the automatic shift schedule while driving through all gears with the shift lever in the D position (See «SERVICE DATA»(ref-224514-S16661207362006031000000) ). Check for abnormal shock and slip at kick-down. 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 position test Shift into the 2 position and fully depress the accelerator pedal and check the following points: Check up-shift operation. Check that the 1 -> 2 up-shift takes place and that the shift point conforms to the automatic shift schedule (See «SERVICE DATA»(ref-224514-S16661207362006031000000) ). HINT: There is no O/D up-shift and lock-up in the 2 position. Check engine braking. While running in the 2 position and 2nd gear, release the accelerator pedal and check the engine braking effect. Check for abnormal noises during acceleration and deceleration, and for shock at up-shift and down-shift. L position test Shift into the L position and fully depress the accelerator pedal and check the following points: Check no up-shift. While running in the L position, check that there is no up-shift to 2nd gear. Check engine braking. While running in the L position, release the accelerator pedal and check the engine braking effect. Check for abnormal noises during acceleration and deceleration. 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. P position test Stop the vehicle on a grade (more than 5°), shift into the P position and release the parking brake. Check that the vehicle does not move.

Scheme 68

Scheme 68: MECHANICAL SYSTEM TESTS

Scheme 69

Scheme 69
  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 and R positions. NOTE: Do the test at normal operating ATF 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 an OBD II scan tool or hand-held tester to the DLC3. Fully apply the parking brake. Using your left foot, keep the brake pedal firmly depressed. 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: 2,300 +/- 250 rpm Do the same test in the R position. Stall speed: 2,300 +/- 250 rpm Evaluation: 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 direct clutch, forward clutch, and 1st and reverse brake. NOTE: Do the test at normal operating ATF 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. Connect an OBD II scan tool or hand-held tester to the DLC3. Fully apply the parking brake. Start the engine and check idle speed. Idle speed: 700 +/- 50 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)

Scheme 70

Scheme 70: HYDRAULIC TEST

Scheme 71

Scheme 71
  1. PERFORM HYDRAULIC TEST Measure the line pressure. NOTE: Do the test at normal operation ATF 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 stopper 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 left side of the trans-axle case and 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 the DLC3. Start the engine and check idling speed. Using your left foot, keep the brake pedal firmly depressed 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. NOTE: Do not continuously run this test for longer than 5 seconds. In the same way, do the test in R position. Specified line pressure LINE PRESSURE SPECIFICATIONS Condition D position kPa (kgf / cm 2 , psi) R position kPa (kgf / cm 2 , psi) Idling 372 to 407 (3.8 to 4.2, 54 to 60) 541 to 636 (5.5 to 6.5, 78 to 92) Stall 1,107 to 1,225 (11.3 to 12.5, 161 to 178) 1,695 to 1,813 (17.3 to 18.5, 246 to 263) Evaluation

Scheme 72

Scheme 72: MANUAL SHIFTING TEST
  1. PERFORM MANUAL SHIFTING TEST HINT: By this test, it can be determined whether the trouble is within the electrical circuit or is a mechanical problem in the transaxle. Disconnect the transmission wire connector. Inspect the manual driving operation. Check that the shift and gear positions correspond to «CORRESPONDING SHIFT AND GEAR POSITIONS»(ref-224522-S28673953332006031000000) . While driving, shift through the L, 2 and D positions. Check that the gear change corresponds to the shift position. CORRESPONDING SHIFT AND GEAR POSITIONS Shift Position Gear Position D 3rd 2 3rd L 3rd R Reverse P Pawl Lock HINT: If the gear positions of the L, 2 and D are difficult to distinguish, do the following road test. If any abnormality is found in the above test, the problem is in the transaxle itself. Connect the transmission wire connector. Clear the DTC (See «DTC CHECK/CLEAR»(ref-224522-S31461245432006031000000) ).

Scheme 73

Scheme 73: TERMINALS OF ECM

Scheme 74

Scheme 74

Scheme 75

Scheme 75: DATA LIST/ACTIVE TEST

Scheme 76

Scheme 76
  1. DATA LIST HINT: According to the DATA LIST displayed by the OBD II scan tool or hand-held tester, you can read the value of the switch, sensor, actuator and so on without parts removal. Reading the DATA LIST as the first step of troubleshooting is one method to shorten labor time. Warm up the engine. Turn the ignition switch off. Connect the OBD II scan tool or hand-held tester to the DLC3. Turn the ignition switch to the ON position. According to the display on tester, read the "DATA LIST".
  2. ACTIVE TEST HINT: Performing the ACTIVE TEST using the hand-held tester allows the relay, VSV, actuator and so on to operate without parts removal. Performing the ACTIVE TEST as the first step of troubleshooting is one method to shorten labor time. It is possible to display the DATA LIST during the ACTIVE TEST. Warm up the engine. Turn the ignition switch off. Connect the hand-held tester to the DLC3. Turn the ignition switch to the ON position. According to the display on tester, perform the "ACTIVE TEST". HINT: The pressure values in ACTIVE TEST and HYDRAULIC TEST are different from each other.

DIAGNOSTIC TROUBLE CODE CHART

If a DTC is displayed during the DTC check, check DIAGNOSTIC DTC LIST .

Scheme 77

Scheme 77: DIAGNOSTIC TROUBLE CODE CHART
DTCDescription
DTC P0705TRANSMISSION RANGE SENSOR CIRCUIT MALFUNCTION (PRNDL INPUT)
DTC P0710, P0712, P0713TRANSMISSION FLUID TEMPERATURE SENSOR "A" CIRCUIT, LOW INPUT & HIGH INPUT
DTC P0711TRANSMISSION FLUID TEMPERATURE SENSOR "A" PERFORMANCE
DTC P0717TURBINE SPEED SENSOR CIRCUIT NO SIGNAL
DTC P0724BRAKE SWITCH "B" CIRCUIT HIGH
DTC P0741TORQUE CONVERTER CLUTCH SOLENOID PERFORMANCE (SHIFT SOLENOID VALVE SL)
DTC P0751SHIFT SOLENOID "A" PERFORMANCE (SHIFT SOLENOID VALVE S1)
DTC P0756SHIFT SOLENOID "B" PERFORMANCE (SHIFT SOLENOID VALVE S2)
DTC P0787, P0788SHIFT/TIMING SOLENOID LOW/HIGH (SHIFT SOLENOID VALVE ST)
DTC P0973, P0974SHIFT SOLENOID "A" CONTROL CIRCUIT LOW/HIGH (SHIFT SOLENOID VALVE S1)
DTC P0976, P0977SHIFT SOLENOID "B" CONTROL CIRCUIT LOW/HIGH (SHIFT SOLENOID VALVE S2)
DTC P2716PRESSURE CONTROL SOLENOID "D" ELECTRICAL (SHIFT SOLENOID SLT)
DTC P2769, P2770TORQUE CONVERTER CLUTCH SOLENOID CIRCUIT LOW/HIGH (SHIFT SOLENOID VALVE SL)

DIAGNOSTIC DTC LIST

PROBLEM SYMPTOMS TABLE

HINT

If a normal code is displayed during the DTC check but the trouble still occurs, check the circuits for each symptom in the order given in (Scheme 78), (Scheme 79) and (Scheme 80).

The Matrix Chart is divided into 3 chapters.

  1. If the instruction "Proceed to next circuit inspection shown on matrix chart" is given in the flow chart for each circuit, proceed to the circuit with the next highest number in the table to continue the check.
  2. If the trouble still occurs even though there are no abnormalities in any of the other circuits, then check and replace the ECM.

CHAPTER 1: ELECTRONIC CIRCUIT MATRIX CHART

Scheme 78

Scheme 78

Chapter 2: On-vehicle Repair

Scheme 79

Scheme 79

Chapter 3: Off-vehicle Repair

Scheme 80

Scheme 80

CIRCUIT DESCRIPTION

The park/neutral position switch detects the shift lever position and sends signals to the ECM.

Scheme 81

Scheme 81: CIRCUIT DESCRIPTION

The ATF temperature sensor converts the fluid temperature into a resistance value which is input into the ECM.

Scheme 82

Scheme 82: CIRCUIT DESCRIPTION

The ATF temperature sensor converts fluid temperature into a resistance value which is input into the ECM.

Scheme 83

Scheme 83: CIRCUIT DESCRIPTION

INSPECTION PROCEDURE

HINT

According to the DATA LIST displayed by the OBD II scan tool or hand-held tester, the value of the switches, sensors, actuators and so on can be read without part removal. Reading the DATA LIST as the first step of troubleshooting is one method to shorten labor time.

  1. Warm up the engine.
  2. Turn the ignition switch off.
  3. Connect the OBD II scan tool or hand-held tester to the DLC3.
  4. Turn the ignition switch to the ON position.
  5. Push the "ON" button of the OBD II scan tool or the hand-held tester.
  6. When using the hand-held tester: Select the item "DIAGNOSIS/ENHANCED OBD II/DATA LIST".
  7. According to the display on the tester, read the "DATA LIST".
ItemMeasurement Item/Range (display)Normal Condition
AT FLUID TEMPATF Temp. Sensor Value/min.: -40°C (-40°F) max.: 215°C (419°F)Approx. 80°C (176°F) (After Stall Test)

AT Fluid Temperature Specifications

HINT

When DTC P0712 is output and the OBD II scan tool or hand-held tester output is 150°C (302°F), there is a short circuit.

When DTC P0713 is output and the OBD II scan tool or hand-held tester output is -40°C (-40°F), there is an open circuit.

Measure the resistance between terminal OIL (OT) and body ground.

Temperature DisplayedMalfunction
40°C (-40°F)Open circuit
150°C (302°F) or moreShort circuit

Temperature Specifications

HINT

If a circuit related to the ATF temperature sensor becomes open, P0713 is immediately set (in 0.5 second).

When P0713 is set, P0711 cannot be detected.

It is not necessary to inspect the circuit when P0711 is set.

  1. CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P0711) Connect the OBD II scan tool or the hand-held tester to the DLC3. Turn the ignition switch to the ON position and push the OBD II scan tool or the hand-held tester main switch ON. When using the hand-held tester: Select the item "DIAGNOSIS/ENHANCED OBD II/DTC INFO/CURRENT CODES". Read the DTCs using the OBD II scan tool or the hand-held tester. Result: DTC OUTPUT SPECIFICATIONS Display (DTC output) Proceed to Only "P0711" is output A "P0711" and other DTCs B HINT: If any other codes besides "P0711" are output, perform troubleshooting for those DTCs first. B: GO TO RELEVANT DTC CHART (See «DIAGNOSTIC TROUBLE CODE CHART»(ref-224522-S36880948192006031000000) ) A: GO TO NEXT STEP
  2. CHECK TRANSAXLE FLUID LEVEL (See «ON-VEHICLE INSPECTION»(ref-224554-S35343821542006031000000) ) OK: Automatic transaxle fluid level is correct. NG: ADD FLUID OK: REPLACE TRANSMISSION WIRE (ATF TEMPERATURE SENSOR) (See «REPLACEMENT»(ref-224554-S09250066732006031000000) )

This sensor detects the rotation speed of the input turbine. By comparing the input turbine speed signal (NT) with the output shaft speed signal, the ECM detects the shift timing of the gears and appropriately controls the engine torque and hydraulic pressure according to various conditions. Thus, providing smooth gear shift.

Scheme 84

Scheme 84: CIRCUIT DESCRIPTION

The purpose of this circuit is to prevent the engine from stalling while driving in lock-up condition, when brakes are suddenly applied.

When the brake pedal is depressed, this switch sends a signals to the ECM. Then the ECM cancels the operation of the lock-up clutch while braking is in progress.

Scheme 85

Scheme 85: CIRCUIT DESCRIPTION

Shift solenoid valve ST is switched ON-OFF by a signal from ECM so that let in or out timing of 2nd brake is adjusted by operating orifice control valve. Therefore, shift solenoid valve ST operates when letting in or out reverse clutch.

If it is broken, the shift shock becomes big.

Scheme 86

Scheme 86: CIRCUIT DESCRIPTION

Shifting from 1st to O/D is performed in combination with ON and OFF of the shift solenoid valve S1 and S2 controlled by ECM. If an open or short circuit occurs in either of the solenoid valves, the ECM controls the remaining normal solenoid valve to allow the vehicle to be operated smoothly (Fail safe function). Fail safe function

If either of the solenoid valve circuits develops an open or short, the ECM turns the other solenoid valve ON and OFF to shift to the gear positions (Scheme 87) 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 (Scheme 87)must be done (In the case of a short circuit, the ECM stops sending current to the short circuited solenoid).

Scheme 87

Scheme 87: CIRCUIT DESCRIPTION

Scheme 88

Scheme 88

See CIRCUIT DESCRIPTION .

Scheme 89

Scheme 89: CIRCUIT DESCRIPTION

The throttle pressure that is applied to the primary regulator valve (which modulates the line pressure) causes the solenoid valve SLT, under electronic control, to precisely and minutely modulate and generate the line pressure according to the extent of the accelerator pedal depressed or the output of engine power.

This controls the line pressure and provides smooth shifting. Upon receiving a signal of the throttle valve opening angle, the ECM controls the line pressure by sending a predetermined (*) duty ratio to the solenoid valve, modulating the line pressure and generating throttle pressure. (*): Duty Ratio

Scheme 90

Scheme 90: CIRCUIT DESCRIPTION

The duty ratio is the ratio of the period of continuity in one cycle. For example, if A is the period of continuity in one cycle, and B is the period of non-continuity, then

Duty Ratio = A/(A+B) x 100 (%)

Scheme 91

Scheme 91

Scheme 92

Scheme 92

The shift solenoid valve SL is turned "ON" and "OFF" by signals from the ECM in order to control the hydraulic pressure operation, the lock-up relay valve, which then the controls operation of the lock-up clutch. Fail safe function

If the ECM detects a malfunction, it turns the shift solenoid valve SL OFF.

Scheme 93

Scheme 93: CIRCUIT DESCRIPTION

The O/D main switch (transmission control switch) is a momentary type switch. When pressing the O/D main switch, the O/D OFF indicator light lights up and the ECM prohibits shifting into O/D, and when pressing it once again, the O/D OFF indicator light goes off and the ECM allows shifting into O/D. Turning the IG switch OFF will reset the O/D OFF indicator light.

Scheme 94

Scheme 94: WIRING DIAGRAM

Scheme 95

Scheme 95: INSPECTION PROCEDURE

Scheme 96

Scheme 96

Scheme 97

Scheme 97

Scheme 98

Scheme 98

Scheme 99

Scheme 99
  1. CHECK HARNESS AND CONNECTOR (TRANSMISSION CONTROL SWITCH - BODY GROUND) Disconnect the transmission control switch connector of shift lever assy. Measure the resistance according to the value(s) in «CHECK HARNESS AND CONNECTOR (TRANSMISSION CONTROL SWITCH - BODY GROUND) RESISTANCE SPECIFICATIONS»(ref-224522-S05359777662006031000000). Standard: CHECK HARNESS AND CONNECTOR (TRANSMISSION CONTROL SWITCH - BODY GROUND) RESISTANCE SPECIFICATIONS Tester connection Specified Condition 4 - Body ground Below 1 ohm NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (See «ELECTRONIC CIRCUIT INSPECTION PROCEDURE»(ref-224507-S11067076722006031000000) ) OK: GO TO NEXT STEP
  2. INSPECT TRANSMISSION CONTROL SWITCH Measure the resistance according to the value(s) in (Scheme 96). Standard: NG: REPLACE TRANSMISSION CONTROL SWITCH OK: GO TO NEXT STEP
  3. CHECK HARNESS AND CONNECTOR (TRANSMISSION CONTROL SWITCH - ECM) Connect the transmission control switch connector of shift lever assy. Disconnect the ECM connector. Measure the resistance according to the value(s) in (Scheme 98). Standard: NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (See «ELECTRONIC CIRCUIT INSPECTION PROCEDURE»(ref-224507-S11067076722006031000000) ) OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE (see «PROBLEM SYMPTOMS TABLE»(ref-224522-S04859416452006031000000) )