Description

IMPROPER SHIFTING TO 4TH GEAR POSITION OR IMPROPER TORQUE CONVERTER CLUTCH OPERATION
- This is a "failure" item indicated by the Malfunction Indicator Lamp (MIL).
- This is indicated when the vehicle is being driven at any gear position other than 4th while the A/T control unit is instructing the A/T to shift the gear in the 4th position. Also, this is indicated when the vehicle is being driven without the torque converter clutch locked up while the A/T control unit is instructing the A/T to lock up the torque converter clutch.
- The detected item, "A/T 4TH OR TCC", is not determined as a fault unless the A/T control unit self-diagnosis system is in the "No Failure" condition. When "A/T 4TH OR TCC" is displayed, it indicates that the gears are not properly shifted. The problem is not caused by electrical failure of the A/T (circuits open or shorted) but by mechanical failure (control valve sticking, improper solenoid valve operation, malfunctioning oil pump or torque converter clutch, etc.).