NO.6 LOW MAXIMUM SPEED AND POOR ACCELERATION [5R55S]

id0503c1801100

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, the malfunction is in the engine control system.

1.  Clutch slippage, burned

•  Line pressure low

•  Shift solenoid D malfunction

•  Shift solenoid A malfunction

•  Shift solenoid B malfunction

•  Shift solenoid C malfunction

•  Pressure control solenoid A, B and C malfunction

•  Body ground malfunction

•  Control valve body malfunction

2.  Signal malfunction

•  OSS sensor malfunction

•  Sensor ground malfunction

•  Accelerator pedal position sensor malfunction

•  TSS sensor malfunction

3.  Transmission fixed in 4GR (Operation of fail-safe function)

•  Short or open circuit in wiring

•  Poor connection of connector

•  Electronic parts of output and input system have malfunction

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

•  Torque converter have malfunction (Poor operation, stuck)

•  TFT sensor malfunction (Short or open circuit)

5.  Digital TR sensor adjustment incorrect

Note

•  Before the following the troubleshooting steps, make sure that the Automatic Transmission On-Board Diagnostic and Automatic Transmission Basic Inspections are conducted.
(See BASIC INSPECTION [5R55S].)

Diagnostic procedure

STEP	INSPECTION		ACTION
1	Go to No.12 “LACK/LOSS OF POWER-ACCELERATION/CRUISE”. (See NO.12 LACK/LOSS OF POWER-ACCELERATION/CRUISE [WL-C, WE-C].) Is the CIS system normal?	Yes	Go to the next step.
1		No	Repair or replace any malfunctioning parts.
2	Disconnect the AT connector. Does the vehicle operate as follows? D range: 4GR (fixed) R position: Reverse	Yes	Go to the next step.
2		No	Clean and inspect main control, if parts are damaged replace main control. If the problem remains, overhaul the transmission and repair or replace any malfunctioning parts.
3	Drive the vehicle in D range. Does the vehicle start from stop in first gear? Check the value at the following TCM PIDs using the IDS/PDS. • GR_CM • GEAR	Yes	Go to the next step.
3		No	Check the value at the following. (See PCM INSPECTION (Thailand, General (L.H.D. R.H.D.) specs.) [WL-C, WE-C].) (See PID/DATA MONITOR INSPECTION [5R55S].) PCM PIDs (using IDS/PDS): • APP1 • APP2 • VSS TCM PIDs (using IDS/PDS): • TSS • ISS • OSS • TR_D Repair or replace any malfunctioning parts.
4	Inspect the value at the following TCM PIDs using the IDS/PDS. • SSA • SSB • SSC • SSD Are the PID values normal?	Yes	Inspect the shift solenoids for sticking. • If the shift solenoids are normal, go to the next step.
4		No	Check the value at the following. PCM PIDs (using IDS/PDS): • APP TCM PIDs (using IDS/PDS): • OSS • ISS • TSS • TR_D
5	Is the line pressure normal? (See MECHANICAL SYSTEM TEST [5R55S].)	Yes	Go to the next step.
5		No	Repair or replace any malfunctioning parts according to the inspection results.
6	Perform the stall test. (See MECHANICAL SYSTEM TEST [5R55S].) Is the stall speed normal?	Yes	Reverify symptoms of malfunctioning.
6		No	Overhaul the transmission and repair or replace any malfunctioning parts.
7	• Verify test results. ― If normal, return to the diagnostic index to service any additional symptoms. ― If the malfunction remains, inspect the related Service Information and perform repair or diagnosis. • If the vehicle repaired, the troubleshooting is completed. • If the vehicle the not repaired or additional diagnostic information is not available, replace the TCM.