NO.14 ENGINE FLARES UP OR SLIPS WHEN UPSHIFTING OR DOWNSHIFTING [5R55S]

id0503c1801900

14

Engine flares up or slips when upshifting or downshifting

DESCRIPTION

•  When accelerator pedal is depressed for driving, engine speed increases but vehicle speed increases slowly.

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

POSSIBLE CAUSE

•  The clutch is slipping because it is stuck or it line pressure is low.

1.  Clutch stuck, slippage (forward clutch, 3–4 clutch, 2–4 brake band, one-way clutch)

•  Line pressure low

•  Incorrect fluid level

•  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

•  IAT sensor malfunction

3.  Poor operation of mechanical pressure

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	Is the shift point normal?	Yes	Go to the next step.
1	Is the shift point normal?	No	Go to symptom troubleshooting No.9 “ABNORMAL SHIFTING”.
2	Check the value at the following PCM PIDs using the IDS/PDS. (See PCM INSPECTION [WL-C, WE-C].) • APP • ACT Are the PID values normal?	Yes	Go to the next step.
2		No	Repair or replace any malfunctioning parts.
3	Disconnect the TCM connector. Is the resistance between TCM ground terminal CO and body ground, and between TCM ground terminal CL and body ground less than 5.0 ohms?	Yes	Go to the next step.
3		No	Repair the wiring harness. Reconnect the TCM connector.
4	Inspect PCA, PCB and PCC PIDs value. (See PID/DATA MONITOR INSPECTION [5R55S].) Are the PCA, PCB and PCC PID values normal?	Yes	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.
4		No	Repair or replace any malfunctioning parts.
5	• 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.