14

Engine flares up or slips when upshifting or downshifting

DESCRIPTION

• When the accelerator pedal is depressed for acceleration from standstill, engine speed increases but the vehicle speed increases slowly.

• When the accelerator pedal is depressed while driving, engine speed increases but the vehicle speed does not.

POSSIBLE CAUSE

• There is clutch slippage because the clutch is stuck or the line pressure is low.

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

• Line pressure low

• Incorrect throttle position signal

• Incorrect accelerator pedal position signal

• Incorrect engine speed signal

• Incorrect engine coolant temperature signal

• Incorrect engine torque signal

• VSS malfunction

• Turbine sensor malfunction

• Sensor GND malfunction

• Shift solenoid A malfunction

• Shift solenoid B malfunction

• Shift solenoid C malfunction

• Shift solenoid D malfunction

• Shift solenoid E malfunction

• Line pressure control solenoid malfunction

• TCC control solenoid malfunction

• Shift solenoid F malfunction

• Shift solenoid G malfunction

• Body GND malfunction

• Control valve body malfunction

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

• Is the line pressure normal?

  (See MECHANICAL SYSTEM TEST[SJ6A-EL].)

Yes

Go to the next step.

No

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

2

• Is shift point normal?

  (See ROAD TEST [SJ6A-EL].)

Yes

Go to the next step.

No

Go to No.9 “ABNORMAL SHIFTING”.

3

• Access the following PCM PIDs using the M-MDS.

• RPM

• APP

• TP

• ECT

• ENG_TRQ

• Are PIDs value normal?

Yes

Go to the next step.

No

Inspect and repair suspected PID related part.

4

• Stop the engine.

• Inspect following solenoids.

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

• Shift solenoid A

• Shift solenoid B

• Shift solenoid C

• Shift solenoid D

• Shift solenoid E

• Line pressure control solenoid

• TCC control solenoid

• Shift solenoid F

• Shift solenoid G

• Are they 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 control valve body.

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

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

5

• Inspect the coupler component for open or short.

• Are coupler component normal?

Yes

Go to the next step.

No

Replace the coupler component.

6

• Inspect the ATF condition.

• Are a large amount of specks found?

Yes

Replace the transmission.

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

No

Replace the control valve body.

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

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

7

• 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.