NO.9 ABNORMAL SHIFTING [SJ6A-EL]

id050307801400

9

Abnormal shifting

DESCRIPTION

•  Shift incorrectly (incorrect shift pattern).

POSSIBLE CAUSE

•  There is a malfunction in the signal circuit which controls shifting (Throttle position signal, turbine sensor, VSS), the control valve is stuck, or the clutch circuit is stuck.

―  Clutch slippage, burnt (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

•  TFT sensor malfunction

•  Line pressure control solenoid malfunction

•  Body GND malfunction

•  Control valve body malfunction

•  TCM malfunction

―  Wheel speed signal malfunction

•  Tire of a different diameter from the standard tire is installed

•  ABS wheel-speed sensor 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].)

•  If a tire of a different diameter from the standard tire is installed, the TCM determines that the driving mode is the AAS mode, and may change to a different shift timing from the normal timing.

Diagnostic procedure

STEP	INSPECTION		ACTION
1	Verify tire condition. • Inspect the tire size and air pressure. • Is the tire of specified size and air pressure?	Yes	Go to the next step.
1		No	Replace with a specified tire size or adjust the air pressure of each specified tire to the specified value.
2	Inspect the vehicle wheel-speed signal. • Display the following DSC CM PIDs using the M-MDS. (See ON-BOARD DIAGNOSIS [DYNAMIC STABILITY CONTROL (DSC)].) ― WSPD_LF ― WSPD_LR ― WSPD_RF ― WSPD_RR • Are the monitoring values displayed uniformly while driving?	Yes	Go to the next step.
2		No	Perform the following inspections: ABS wheel-speed sensor installation inspection ― Is the ABS wheel-speed sensor installation normal? ABS sensor rotor installation inspection ― Is the ABS sensor rotor installed twisted? (may cause output of abnormal wave pattern at high speeds.) ― Are there missing teeth on the sensor rotor? If there is any malfunction, repair or replace the malfunctioning location.
3	• Inspect for continuity between the TCM terminal 1P, 1X and battery negative terminal. • Is there continuity?	Yes	Go to the next step.
3		No	Repair or replace ground circuit.
4	• Access the following PCM PIDs using the M-MDS. ― RPM ― APP ― TP ― ECT • Are PIDs value normal?	Yes	Go to the next step.
4		No	Inspect and repair suspected PID related part.
5	• Inspect the TFT sensor. (See TRANSMISSION FLUID TEMPERATURE (TFT) SENSOR INSPECTION [SJ6A-EL].) • Is the TFT sensor normal?	Yes	Go to the next step.
5		No	Replace the TFT sensor.
6	• Inspect the line pressure control solenoid. (See SOLENOID VALVE INSPECTION [SJ6A-EL].) • Is the line pressure control solenoid normal?	Yes	Inspect the TCM terminal for bend, damage, corrosion or poor contact.
6		No	Inspect the coupler component. If normal, replace suspected solenoid. (See Automatic Transmission Workshop Manual 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.