Automatic Transaxle: Overview Nissan Altima L31

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Conditions for Lock-up Operation

When vehicle is driven in 4th gear position, vehicle speed and throttle opening are detected. If the detected values fall within the lock-up zone memorized in the TCM, lock-up is performed.

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Overrun Clutch Control Valve Operation

When the solenoid valve is ON, pilot pressure is applied to the overrun clutch control valve. This pushes up the overrun clutch control valve. The line pressure is then shut off so that the clutch does not engage.

When the solenoid valve is OFF, pilot pressure is not generated. At this point, the overrun clutch control valve moves downward by spring force. As a result, overrun clutch operation pressure is provided by the overrun clutch reducing valve. This causes the overrun clutch to engage.

In the 1 position, the overrun clutch control valve remains pushed down so that the overrun clutch is engaged at all times.

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DESCRIPTION

1. The purpose of the test is to determine overall performance of A/T and analyze causes of problems.
2. The road test consists of the following three parts

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1. Check before engine is started
2. Check at idle
3. Cruise test

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1. Before road test, familiarize yourself with all test procedures and items to check.
2. Conduct tests on all items until specified symptom is found. Troubleshoot items which check out No Good after road test. Refer to «ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION»(ref-206576-S40203467022005112500000) , and «TROUBLE DIAGNOSIS FOR SYMPTOMS»(ref-206576-S25882427682005112500000) .

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1. CHECK A/T CHECK (POSITION) INDICATOR LAMP Park vehicle on flat surface. Move selector lever to P position. Turn ignition switch to OFF position. Wait at least 5 seconds. Turn ignition switch to ON position. (Do not start engine.) Does A/T check (position) indicator lamp come on for about 2 seconds? Yes or No Yes: GO TO 2. No: Stop ROAD TEST. Go to «1, A/T CHECK (POSITION) INDICATOR LAMP DOES NOT COME ON»(ref-206576-S21109005872005112500000) .
2. CHECK A/T CHECK (POSITION) INDICATOR LAMP Does A/T check (position) OFF indicator lamp flicker for about 8 seconds?

Yes or No

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1. Yes: Perform self-diagnosis and check NG items on the «DIAGNOSTIC WORKSHEET»(ref-206576-S32280965142005112500000) . Refer to «TCM SELF-DIAGNOSTIC PROCEDURE (NO TOOLS)»(ref-206576-S39240413392005112500000) .
2. No: Turn ignition switch to OFF position. Perform self-diagnosis and note NG items. Refer to «TCM SELF-DIAGNOSTIC PROCEDURE (NO TOOLS)»(ref-206576-S39240413392005112500000) . Go to «2. CHECK AT IDLE»(ref-206576-S29303667152005112500000) .

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1. CHECK ENGINE START Park vehicle on flat surface. Move selector lever to P position. Turn ignition switch to OFF position. Turn ignition switch to START position. Is engine started? Yes or No Yes: GO TO 2. No: Mark the box on the DIAGNOSTIC WORKSHEET. Go to «Engine Cannot Be Started In P and N Position. Continue ROAD TEST.»(ref-206576-S29455410552005112500000)
2. CHECK ENGINE START Turn ignition switch to ACC position. Move selector lever to D, 1, 2 or R position. Turn ignition switch to START position. Is engine started? Yes or No Yes: Mark the box on the DIAGNOSTIC WORKSHEET. Go to «Engine Cannot Be Started In P and N Position. Continue ROAD TEST.»(ref-206576-S29455410552005112500000) . No: GO TO 3.
3. CHECK VEHICLE MOVE Move selector lever to P position. Turn ignition switch to OFF position. Release parking brake. Push vehicle forward or backward. Does vehicle move when it is pushed forward or backward? Apply parking brake. Yes or No Yes: Mark the box on the DIAGNOSTIC WORKSHEET. Go to «3. IN P POSITION, VEHICLE MOVES FORWARD OR BACKWARD WHEN PUSHED»(ref-206576-S13486316672005112500000) . Continue ROAD TEST. No: GO TO 4.
4. CHECK VEHICLE MOVE Start engine. Move selector lever to N position. Release parking brake. Does vehicle move forward or backward? Yes or No Yes: Mark the box on the DIAGNOSTIC WORKSHEET. Go to «4. IN N POSITION, VEHICLE MOVES»(ref-206576-S24681485872005112500000) . Continue ROAD TEST. No: GO TO 5.
5. CHECK SHIFT LOCK Apply foot brake. Move selector lever to R position. Is there large shock when changing from N to R position? Yes or No Yes: Mark the box on the DIAGNOSTIC WORKSHEET. Go to «5. LARGE SHOCK. N --> R POSITION»(ref-206576-S02827813072005112500000) . Continue ROAD TEST. No: GO TO 6.
6. CHECK VEHICLE MOVE Release foot brake for several seconds. Does vehicle creep backward when foot brake is released? Yes or No Yes: GO TO 7. No: Mark the box on the DIAGNOSTIC WORKSHEET. Go to «6. VEHICLE DOES NOT CREEP BACKWARD IN R POSITION»(ref-206576-S18911171622005112500000) . Continue ROAD TEST.
7. CHECK VEHICLE MOVE Move selector lever to D, 2 and 1 positions and check if vehicle creeps forward. Does vehicle creep forward in all three positions? Yes or No Yes: Go to CRUISE TEST . No: Mark the box on the DIAGNOSTIC WORKSHEET. Go to «7. VEHICLE DOES NOT CREEP FORWARD IN D, 3, 2 OR 1 POSITION»(ref-206576-S23379773682005112500000) . Continue ROAD TEST.
8. CRUISE TEST Check all items listed in Parts 1 through 3.

With CONSULT-II

1. Using CONSULT-II, conduct a cruise test and record the result.
2. Print the result and ensure that shifts and lock-ups take place as per Shift Schedule. Refer to «SHIFT SCHEDULE»(ref-206576-S24864084732005112500000)

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1. Turn ignition switch OFF.
2. Connect CONSULT-II to data link connector, which is located in left side dash panel.
3. Turn ignition switch ON.
4. Touch START.
5. Touch A/T
6. Touch DATA MONITOR.
7. Touch MAIN SIGNALS or TCM INPUT SIGNALS.
8. See Numerical Display Barchart Display or Line Graph Display.
9. Touch SETTING to set recording condition (AUTO TRIG or MANU TRIG) and touch BACK.
10. Touch Start.
11. When performing cruise test, touch RECORD.
12. After finishing cruise test part 1, touch STOP.
13. Touch STORE and touch BACK.
14. Touch DISPLAY.
15. Touch PRINT.
16. Check the monitor data printed out.
17. Continue cruise test part 2 and 3.

Without CONSULT-II

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1. Throttle position sensor can be checked by voltage across terminals 41 (W) and 42 (B) of TCM.

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1. CHECK STARTING GEAR (D 1 ) POSITION Drive vehicle for approximately 10 minutes to warm engine oil and ATF up to operating temperature. ATF operating temperature: 50 - 80°C (122 - 176°F) Park vehicle on flat surface. Set gear selector lever to D position. Move selector lever to P position. Start engine. Move selector lever to D position. Accelerate vehicle by constantly depressing accelerator pedal half-way. Does vehicle start from D 1 ? Read gear position. Yes or No Yes: GO TO 2. No: Go to «8. VEHICLE CANNOT BE STARTED FROM»(ref-206576-S05728877162005112500000) D 1 . Continue ROAD TEST.
2. CHECK SHIFT UP (D 1 TO D 2 ) Does A/T shift from D 1 to D 2 at the specified speed? Read gear position, throttle opening and vehicle speed. Specified speed when shifting from D 1 to D 2 : Refer to «Shift Schedule»(ref-206576-S24864084732005112500000) . Yes or No Yes: GO TO 3. No: Go to «9. A/T DOES NOT SHIFT»(ref-206576-S20015328332005112500000) D 1 --> D 2 OR DOES NOT KICKDOWN: D 4 --> D 2 . Continue ROAD TEST.
3. CHECK SHIFT UP (D 2 TO D 3 ) Does A/T shift from D 2 to D 3 at the specified speed? Read gear position, throttle opening and vehicle speed. Specified speed when shifting from D 1 to D 3 : Refer to «Shift Schedule»(ref-206576-S24864084732005112500000) . Yes or No Yes: GO TO 4. No: Go to «10. A/T DOES NOT SHIFT»(ref-206576-S02927353442005112500000) D 2 --> D 3 . Continue ROAD TEST.
4. CHECK SHIFT UP (D 3 TO D 4 ) Does A/T shift from D 3 to D 4 at the specified speed? Read gear position, throttle opening and vehicle speed. Specified speed when shifting from D 3 to D 4 : Refer to «Shift Schedule»(ref-206576-S24864084732005112500000) . Yes or No Yes: GO TO 5. No: Go to «11. A/T DOES NOT SHIFT: D3 --> D4»(ref-206576-S19562502192005112500000) . Continue ROAD TEST.
5. CHECK LOCK-UP (D 4 TO D 4 L/U) Does A/T perform lock-up at the specified speed? Read vehicle speed, throttle opening when lock-up duty becomes 94%. Specified speed when lock-up occurs: Refer to «SHIFT SCHEDULE»(ref-206576-S24864084732005112500000) . Yes or No Yes: GO TO 6. No: Go to «12. A/T DOES NOT PERFORM LOCK-UP»(ref-206576-S31798377852005112500000) . Continue ROAD TEST.
6. CHECK HOLD LOCK-UP Does A/T hold lock-up condition for more than 30 seconds? Yes or No Yes: GO TO 7. No: Go to «13. A/T DOES NOT HOLD LOCK-UP CONDITION»(ref-206576-S15076303982005112500000) .
7. CHECK SHIFT DOWN (D 4 L/U TO D 4 ) Release accelerator pedal. Is lock-up released when accelerator pedal is released? Yes or No Yes: GO TO 8. No: Go to «14. LOCK-UP IS NOT RELEASED»(ref-206576-S07761049582005112500000) . Continue ROAD TEST.
8. CHECK SHIFT DOWN (D 4 TO D 3 ) Decelerate vehicle by applying foot brake lightly. Does engine speed return to idle smoothly when A/T is shifted from D 4 to D 3 ? Read gear position and engine speed. Yes or No Yes: Stop vehicle. Go to «CRUISE TEST - PART 2»(ref-206576-S03869413992005112500000) . No: Go to «15. Engine Speed Does Not Return To Idle»(ref-206576-S28593157782005112500000) (Light Braking D 4 --> D 3 ). Continue ROAD TEST.

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1. CHECK STARTING GEAR (D 1 ) POSITION Confirm gear selector lever is in D position. Accelerate vehicle by half throttle again. Does vehicle start from D 1 ? Read gear position. Yes or No Yes: GO TO 2. No: Go to «16. VEHICLE DOES NOT START FROM»(ref-206576-S18382449752005112500000) D 1 . Continue ROAD TEST.
2. CHECK SHIFT UP AND SHIFT DOWN (D 3 TO D 4 TO D 2 ) Accelerate vehicle to 80 km/h (50 MPH) as shown in illustration. Release accelerator pedal and then quickly depress it fully. Does A/T shift from D 4 to D 2 as soon as accelerator pedal is depressed fully? Read gear position and throttle opening. Yes or No Yes: GO TO 3. No: Go to «9. A/T DOES NOT SHIFT»(ref-206576-S20015328332005112500000) D 1 --> D 2 OR DOES NOT KICKDOWN: D 4 --> D 2 . Continue ROAD TEST.
3. CHECK SHIFT UP (D 2 TO D 3 ) Does A/T shift from D 2 to D 3 at the specified speed? Read gear position, throttle opening and vehicle speed. Specified speed when shifting from D 2 to D 3 : Refer to «Shift Schedule»(ref-206576-S24864084732005112500000) . Yes or No Yes: GO TO 4. No: Go to «10. A/T DOES NOT SHIFT»(ref-206576-S02927353442005112500000) D 2 --> D 3 . Continue ROAD TEST.

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1. 4. CHECK SHIFT UP (D 3 TO D 4 ) AND ENGINE BRAKE Release accelerator pedal after shifting from D2 to D3. Does A/T shift from D3 to D4 and does vehicle decelerate by engine brake? Read gear position, throttle opening and vehicle speed. Yes or No Yes: Stop vehicle. Go to «CRUISE TEST - PART 3»(ref-206576-S20089555582005112500000) . No: Go to «11. A/T DOES NOT SHIFT: D3 --> D4»(ref-206576-S19562502192005112500000) . Continue ROAD TEST.

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1. VEHICLE SPEED (D4) POSITION Confirm gear selector lever is in D position. Accelerate vehicle using half-throttle to D4. Release accelerator pedal. Move gear selector lever from D position to 3 position while driving in D4. Does A/T shift from D4 to 3? Read gear position and vehicle speed. Yes or No Yes: GO TO 2. No: Go to «16. VEHICLE DOES NOT START FROM»(ref-206576-S18382449752005112500000) D 1 . Continue ROAD TEST.
2. CHECK ENGINE BRAKE Does vehicle decelerate by engine brake? Yes or No Yes: GO TO 3. No: Go to «15. Engine Speed Does Not Return To Idle»(ref-206576-S28593157782005112500000) (Light Braking D 4 --> D 3 ). Continue ROAD TEST.
3. CHECK SHIFT DOWN (3 3 TO 2 2 ) Move selector lever from 3 to 2 position while driving in 3 3 . Does A/T shift from 3 3 to 2 2 ? Read gear position. Yes or No Yes: GO TO 4. No: Go to «18. A/T DOES NOT SHIFT»(ref-206576-S13577884872005112500000) 3 3 --> 2 2 , WHEN SELECTOR LEVER 3 --> 2 POSITION. Continue ROAD TEST.
4. CHECK ENGINE BRAKE Does vehicle decelerate by engine brake? Yes or No Yes: GO TO 5. No: Go to «15. Engine Speed Does Not Return To Idle»(ref-206576-S28593157782005112500000) (Light Braking D 4 --> D 3 ). Continue ROAD TEST
5. CHECK SHIFT DOWN (2 2 TO 1 1 ) Move selector lever from 2 to 1 position while driving in 2 2 . Does A/T shift from 2 2 to 1 1 position? Read gear position. Yes or No Yes: GO TO 6. No: Go to «19, A/T Does Not Shift»(ref-206576-S04349997102005112500000) 2 2 --> 1 1 , When Selector Lever 2 --> 1 Position. Continue ROAD TEST.
6. CHECK ENGINE BRAKE Does vehicle decelerate by engine brake? Yes or No Yes: Stop vehicle. Perform self-diagnosis. Refer to «TCM SELF-DIAGNOSTIC PROCEDURE (NO TOOLS)»(ref-206576-S39240413392005112500000) . No: Go to «20. VEHICLE DOES NOT DECELERATE BY ENGINE BRAKE»(ref-206576-S38804506462005112500000) . Continue ROAD TEST.

The A/T fluid temperature sensor detects the A/T fluid temperature and sends a signal to the TCM.

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The revolution sensor detects the revolution of the idler gear parking pawl lock gear and emits a pulse signal. The pulse signal is sent to the TCM which converts it into vehicle speed.

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The engine speed signal is sent from the ECM to the TCM.

The torque converter clutch solenoid valve is activated, with the gear in D4, by the TCM (in response to signals sent from the vehicle speed and the ECM (throttle opening). Lock-up piston operation will then be controlled.

Lock-up operation, however, is prohibited when A/T fluid temperature is too low.

When the accelerator pedal is depressed (less than 2/8) in lock-up condition, the engine speed should not change abruptly. If there is a big jump in engine speed, there is no lock-up.

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1. This is an OBD-II self-diagnostic item and not available in TCM self-diagnosis.
2. This malfunction will not be detected while the A/T check position indicator lamp is indicating another self-diagnosis malfunction.
3. This malfunction is detected when the A/T does not shift into fourth gear position or the torque converter clutch does not lock up as instructed by the TCM. This is not caused by electrical malfunction (circuits open or shorted) but by mechanical malfunction such as control valve sticking, improper solenoid valve operation, malfunctioning oil pump or torque converter clutch, etc.

The line pressure solenoid valve regulates the oil pump discharge pressure to suit the driving condition in response to a signal sent from the TCM.

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Shift solenoid valves A and B are turned ON or OFF by the TCM in response to signals sent from the park/neutral position (PNP) switch, vehicle speed and ECM (throttle opening). Gears will then be shifted to the optimum position.

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Shift solenoid valves A and B are turned ON or OFF by the TCM in response to signals sent from the park/neutral position (PNP) switch, vehicle speed and ECM (throttle opening). Gears will then be shifted to the optimum position.

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The throttle position sensor [accelerator pedal position (APP) sensor] is part of the system that controls throttle position. This system also uses an electric throttle control actuator, which consists of a throttle control motor and throttle position sensors. Accelerator pedal position signal is sent to the ECM.

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The overrun clutch solenoid valve is activated by the TCM in response to signals sent from the park/neutral position (PNP) switch, overdrive control switch, vehicle speed and ECM (throttle opening). The overrun clutch operation will then be controlled.

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CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle multiplex communication line with high data communication speed and excellent error detection ability. Many electronic control units are equipped onto a vehicle, and each control unit shares information and links with other control units during operation (not independent). In CAN communication, control units are connected with 2 communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring. Each control unit transmits/receives data but selectively reads required data only.

The A/T fluid temperature sensor detects the A/T fluid temperature and sends a signal to the TCM.

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The vehicle speed sensor. MTR is built into the speedometer assembly. The sensor functions as an auxiliary device to the revolution sensor when it is malfunctioning. The TCM will then use a signal sent from the vehicle speed sensor MTR.

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The turbine revolution sensor detects forward clutch drum RPM (revolutions per minute). It is located on the input side of the automatic transaxle. The vehicle speed sensor A/T (Revolution sensor) is located on the output side of the automatic transaxle. With the two sensors, input and output RPMs are accurately detected. The result is optimal shift timing during deceleration and improved shifting.

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The TCM consists of a microcomputer and connectors for signal input and output and for power supply. The unit controls the A/T.

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The TCM consists of a microcomputer and connectors for signal input and output and for power supply. The unit controls the A/T.

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1. Park/neutral position (PNP) switch The park/neutral (PNP) switch assembly includes a transmission range switch. The transmission range switch detects the selector lever position and sends a signal to the TCM.
2. 3 position switch Detects the A/T selector lever in 3 position and sends a signal to the TCM.
3. Throttle position sensor [accelerator pedal position (APP) sensor] The throttle position sensor [accelerator pedal position (APP) sensor] is part of the system that controls the throttle position. This system also uses an electric throttle control actuator, which consists of a throttle control motor and throttle position sensors. Accelerator pedal position signal is sent to the ECM.

1. The mechanical key interlock mechanism also operates as a shift lock: With the key switch turned to ON, the selector lever cannot be shifted from P (parking) to any other position unless the brake pedal is depressed. With the key removed, the selector lever cannot be shifted from P to any other position. The key cannot be removed unless the selector lever is placed in P.
2. The shift lock and key interlock mechanisms are controlled by the ON-OFF operation of the shift lock solenoid and by the operation of the rotator and slider located inside the key cylinder.

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