NO.6 LOW MAXIMUM SPEED AND POOR ACCELERATION [SJ6A-EL]

id050307801100

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 (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

Diagnostic procedure

STEP

INSPECTION

ACTION
1
•  With the ignition switch at the ON position.
•  Does the gear position indication correspond to the selector lever position?
Yes
Go to the next step.
No
Perform the symptom troubleshooting “NO.27 GEAR POSITION INDICATION ILLUMINATES IN D POSITION”, or “NO.28 GEAR POSITION INDICATION DOES NOT ILLUMINATE IN M POSITION”.
(See NO.27 GEAR POSITION INDICATION ILLUMINATES IN D POSITION [SJ6A-EL].)
(See NO.28 GEAR POSITION INDICATION DOES NOT ILLUMINATE IN M POSITION [SJ6A-EL].)
2
•  Perform the symptom troubleshooting “NO.12 LACK/LOSS OF POWER-ACCELERATION/CRUISE”.
•  Does the engine control system normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
3
•  Stop the engine.
•  Inspect line pressure control solenoid.
•  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.
4
•  Inspect the ATF condition.
•  Are there any metal specks found in ATF?
Yes
•  If a large amount of metal specks are found, overhaul the transmission and repair or replace any malfunctioning parts.
(See Automatic Transmission Workshop Manual [SJ6A-EL].)
•  If a large amount of metal specks are not found, replace the control valve body.
No
Replace the torque converter.
(See TORQUE CONVERTER REMOVAL/INSTALLATION [SJ6A-EL].)
5
•  Verify test results.
―  If normal, return to the diagnostic index to service any additional symptoms.
―  If malfunction remains, inspect the related Service 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. (See TCM REMOVAL/INSTALLATION [SJ6A-EL].)