NO.14 ENGINE FLARES UP OR SLIPS WHEN UPSHIFTING OR DOWNSHIFTING [SJ6A-EL]

id050307801900

14 | Engine flares up or slips when upshifting or downshifting
DESCRIPTION | • When the accelerator pedal is depressed for acceleration from standstill, engine speed increases normally but the vehicle speed increases slowly. • When the accelerator pedal is depressed while driving, engine speed increases but vehicle speed does not increase.
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].)

Diagnostic procedure

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 the malfunctioning part according to the inspection results.
2 | • Is shift point normal? (See ROAD TEST [SJ6A-EL].) | Yes | Go to the next step.
No | Perform the symptom troubleshooting “NO.9 ABNORMAL SHIFTING”. (See NO.9 ABNORMAL SHIFTING [SJ6A-EL].)
3 | • Access the following PCM PIDs using the M-MDS: (See ON-BOARD DIAGNOSTIC TEST [L8, LF].) ― RPM ― APP ― TP ― ECT • Are the PIDs value normal? (See PCM INSPECTION [L8, LF].) | Yes | Go to the next step.
No | Repair or replace the malfunctioning part according to the inspection results.
4 | • Stop the engine. • Inspect the 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 these solenoids normal? | Yes | Inspect the ATF condition. • If a large amount of metal specks are found, overhaul the transmission and repair or replace any malfunctioning parts. (See AUTOMATIC TRANSMISSION REMOVAL/INSTALLATION [SJ6A-EL].) (See Automatic Transmission Workshop Manual [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. (See CONTROL VALVE BODY REMOVAL [SJ6A-EL].)
6 | • Inspect the ATF condition. • Are a large amount of specks found? | Yes | Overhaul the transmission and repair or replace any malfunctioning parts. (See AUTOMATIC TRANSMISSION REMOVAL/INSTALLATION [SJ6A-EL].) (See Automatic Transmission Workshop Manual [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 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].)