6

Low maximum speed and poor acceleration

DESCRIPTION

• Vehicle acceleration is poor at start.

• Delayed acceleration when accelerator pedal is depressed while driving.

POSSIBLE CAUSE

• If the clutch is stuck or does not stay in 4GR, malfunction is in engine circuit.

• Clutch slippage, burnt (C1 clutch, C2 clutch, C3 clutch, B1 brake, B2 brake, B3 brake, B4 brake)

• Line pressure low

• Line pressure control solenoid malfunction

• Control valve body malfunction

• Transmission fixed in 4GR or 5GR (Operation of fail-safe function)

• Short or open circuit in wiring harness

• Poor connection of connector

• Malfunction of electronic parts of output and input system

• Insufficient starting torque (Suspected when in-gear, shift control and engine circuit are normal)

• Torque converter malfunction (Poor operation, stuck)

• Engine output low

NOTE:

• Before following the troubleshooting steps, make sure that the Automatic Transmission On-Board Diagnostic and Automatic Transmission Basic Inspection are conducted. (See BASIC INSPECTION [SJ6A-EL].)

STEP

INSPECTION

ACTION

1

• With the ignition switch at the ON position, does the gear position indicator light indication correspond to the selector lever position?

Yes

Go to the next step.

No

Go to No.27 “GEAR POSITION INDICATOR LIGHT DOES NOT ILLUMINATE IN M RANGE”, or No.28 “GEAR POSITION INDICATOR LIGHT ILLUMINATES IN D RANGE OR P, N, R POSITIONS”.

2

• Go to No.12 “LACK/LOSS OF POWER-ACCELERATION/CRUISE”.

  (See NO.12 LACK/LOSS OF POWER-ACCELERATION/CRUISE [LF].)

• Does engine control system normal?

Yes

Go to the next step.

No

Repair or replace any malfunctioning parts according to the inspection results.

3

• Stop the engine.

• Inspect line pressure control solenoid.

  (See SOLENOID VALVE INSPECTION [SJ6A-EL].)

• Is the line pressure control solenoid normal?

Yes

Go to the next step.

No

Inspect the coupler component.

If normal, replace the control valve body.

(See CONTROL VALVE BODY REMOVAL [SJ6A-EL].)

(See CONTROL VALVE BODY INSTALLATION [SJ6A-EL].)

4

• Remove the torque converter.

  (See TORQUE CONVERTER REMOVAL/INSTALLATION [SJ6A-EL].)

• Inspect the torque converter.

• Is the torque converter normal?

Yes

Inspect the ATF condition.

• If a large amount of metal specks are found, replace the transmission.

  (See AUTOMATIC TRANSMISSION REMOVAL/INSTALLATION [SJ6A-EL].)

• If a large amount of metal specks are not found, replace the control valve body.

  (See CONTROL VALVE BODY REMOVAL [SJ6A-EL].)

  (See CONTROL VALVE BODY INSTALLATION [SJ6A-EL].)

No

Replace the torque converter.

5

• Verify test results.

• If normal, return to the diagnostic index to service any additional symptoms.

• If malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis.

• If the vehicle is repaired, troubleshooting completed.

• If the vehicle is not repaired or additional diagnostic information is not available, replace the TCM.