Automatic Transmission: Overview Suzuki Aerio I

A/T Description

This automatic transaxle is a full automatic type with 3-speed plus overdrive (O/D).

The torque converter is a 3-element, 1-step and 2-phase type and is equipped with an electronically controlled lock-up mechanism.

The gear shift device consists of 3 sets of planetary gear units, 3 disc type clutches, 3 disc type brakes, a band type brake and 3 one-way clutches. The gear shift is done by selecting one of 6 positions ("P", "R", "N", "D", "2" and "L") by means of the select lever installed on the floor. On the shift knob, there is an overdrive (O/D) off switch which prevents shift-up to the overdrive mode.

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Table of Component Operation

COMPONENT OPERATION CHART

A/T Diagnosis General Description

This vehicle is equipped with an electronic transaxle control system, which controls the automatic shift up and shift down timing, TCC operation, etc. suitably to vehicle driving conditions.

TCM has an On-Board Diagnosis System which detects a malfunction in this system and abnormality of those parts that influence the engine exhaust emission.

When diagnosing a trouble in transaxle including this system, be sure to have full understanding of the outline of ON-BOARD DIAGNOSTIC SYSTEM DESCRIPTION and each item in PRECAUTIONS IN DIAGNOSING TROUBLE and execute diagnosis according to A/T SYSTEM CHECK to obtain correct result smoothly.

On-Board Diagnostic System Description

For automatic transaxle control system, TCM has following functions.

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1. When TCM detects a malfunction in A/T control system, it stores malfunction DTC and at the same time transmits DTC of that malfunction to ECM. (Based on this signal, ECM turns ON malfunction indicator lamp (MIL) (1) and stores DTC / freeze frame data in its memory.)
2. If no malfunction is detected in the next driving cycles after detecting malfunction, TCM immediately halts to transmit DTC of that malfunction to ECM, however, DTC stored in TCM memory will remain. If ECM receives no DTC of malfunction for 3 driving cycles continuously, it turns MIL off although DTC stored in ECM memory will also remain.
3. It is possible to communicate with ECM and/or TCM through data link connector (DLC) (2) by using SUZUKI scan tool (3). (Diagnostic information can be checked and erased by using scan tool.)
4. It is also possible to check DTC stored in TCM memory by displaying DTC on digital display odometer (1). DTC is displayed on odometer by connecting diagnosis switch terminal (2) with ground terminal (3) of monitor connector (color in Blue) (4), with reset button (5) pressed. If no malfunction DTC is stored in TCM memory, DTC No. 12 is displayed. If one or more DTCs are stored in TCM memory, they are displayed 3 seconds each sequentially. After all DTCs are displayed, they are displayed in the same manner again.

Operation of Shift Solenoid Valves and TCC Solenoid Valve

OPERATION OF SHIFT SOLENOID VALVES AND TCC SOLENOID VALVE CHART

VALVE STATUS

System Description

TCM turns TCC solenoid OFF under any of the following conditions.

1. Engine coolant temperature is lower than 37 °C (99 °F).
2. Lock-up off signal by cruise control module is ON.

TCM detects the following DTCs

P0717 / P0722 / P0727 / P0962 / P0963 / P0973 / P0974 / P0976 / P0977 / P1700 / P1702 / P1730 / P2763 / P2764

Operation Check

Shift solenoid valve-A (No. 1) and - B (No. 2)

1. Check that solenoid valve (1) actuate with click sound when battery voltage is conducted.
2. Apply oiler (2) to solenoid valve (1) and give compression by hands and then check to be sure that transaxle fluid from oiler does not come out of holes in solenoid valve when battery voltage is not conducted.
3. Under the same conditions, conduct battery voltage and then make sure that fluid comes out with vigor. If check result is not as described, replace shift solenoid valve.

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TCC solenoid valve

1. Check that solenoid valve (1) actuate with click sound when battery voltage is conducted.
2. Apply oiler (2) to solenoid valve (1) and give compression by hands and then check to be sure that transaxle fluid from oiler does not come out of holes in solenoid valve when battery voltage is conducted.
3. Under the same conditions, release battery voltage and then make sure that fluid comes out with vigor. If check result is not as described, replace shift solenoid valve.

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Check pressure control solenoid valve operation in the either manner of the following.

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1. Connect pressure control solenoid valve (1) with regulated DC power supply (2) as shown in the figure.
2. Turn regulated DC power supply switch ON and increase voltage of power supply keeping current within 1.0 A.
3. Check for gradual movement of valve (3) in the direction of arrow "A" as voltage is increased.
4. Check movement of valve (3) in the direction of arrow "B" as voltage is decreased.
5. Turn power supply switch OFF. CAUTION: Do not pass current 1.0 A or more, or pressure control solenoid is burned out.

1st / Reverse Brake and One-Way No. 2 Clutch Operation Check

Reference: AUTOMATIC TRANSAXLE UNIT DISASSEMBLY

Reference: AUTOMATIC TRANSAXLE UNIT ASSEMBLY

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1. Check that one-way No. 2 clutch (1) turns freely when turned counterclockwise [A] and looks when turned clockwise [B].

Underdrive Clutch and One-Way No. 3 Clutch Operation Check

Reference: AUTOMATIC TRANSAXLE UNIT DISASSEMBLY

Reference: AUTOMATIC TRANSAXLE UNIT ASSEMBLY

Scheme 9

1. Install one-way No. 3 clutch (1) to underdrive clutch drum (2).
2. Check that one-way No. 3 clutch turns freely when turned counterclockwise [A] and locks when turned clockwise [B].

Reduction Drive Gear Assembly Operation Check

Reference: AUTOMATIC TRANSAXLE UNIT DISASSEMBLY

Reference: AUTOMATIC TRANSAXLE UNIT ASSEMBLY

Measure starting torque of reduction drive gear, using spring force gauge, attach cord at groove of outer race. If starting torque is out of specification, replace reduction drive gear assembly.

Starting torque of reduction drive gear

0.3 - 0.8 N.m (0.03 - 0.08 kgf-m, 0.22 - 0.58 lb-ft)

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