Automatic Transmission System (For 1Gd-Ftv) Fail-Safe Chart

  1. Fail-safe

Automatic Transmission System (For 1Gd-Ftv) -- Fail-Safe Chart



Fail-safe
This function minimizes the loss of operation when any abnormality occurs in a sensor or solenoid.

Fail-safe Control List
Malfunction Part
Function
Transmission revolution sensor (NT)
During a transmission revolution sensor (NT) malfunction, shift control is performed based on the transmission revolution sensor (SP2) signal.
Transmission revolution sensor (SP2)
During a transmission revolution sensor (SP2) malfunction, shift control is performed based on the wheel speed sensor signal.
ATF temperature sensors (No. 1 and No. 2)
During an ATF temperature sensor malfunction, up-shifting to 5th and 6th is prohibited.
Shift solenoid valve SL1, SL2, SL3 and SL4
Stop the conduction of electric power to a failed solenoid and shift gears by turning on/off normal solenoids. If all solenoids are malfunctioning, gears will be selected through mechanical hydraulic circuits.
Shift solenoid valve SLT
During a shift solenoid valve SLT malfunction, the current to the shift solenoid valve is stopped. However, shifting is performed through normal clutch pressure control.
Shift solenoid valve SLU
During a shift solenoid valve SLU malfunction, the current to the shift solenoid valve is stopped. This stops lock-up control, thus decreasing fuel economy.

Shift Solenoid Valve Operation when Normal
Gear Position
1st
2nd
3rd
4th
5th
6th
Shift solenoid valve SL1
ON
ON
ON
ON
OFF
OFF
Shift solenoid valve SL2
OFF
OFF
OFF
ON
ON
ON
Shift solenoid valve SL3
OFF
ON
OFF
OFF
OFF
ON
Shift solenoid valve SL4
OFF
OFF
ON
OFF
ON
OFF

Fail-safe Control Chart
Gear Position under Normal Conditions
1st
2nd
3rd
4th
5th
6th
Shift solenoid valve SL1
ON Malfunction (without Fail-safe Control)*
1st
2nd
3rd
4th
4th
4th
OFF Malfunction (without Fail-safe Control)
1st to N
2nd to N
3rd to N
4th to N
5th
6th
Fail-safe Control during OFF Malfunction
Fixed in 3rd or 5th
Shift solenoid valve SL2
ON Malfunction (without Fail-safe Control)*
1st to 4th
2nd to 4th
3rd to 4th
4th
5th
6th
OFF Malfunction (without Fail-safe Control)
1st
2nd
3rd
4th to 1st
5th to N
6th to N
Fail-safe Control during OFF Malfunction
Fixed in 2nd or 3rd
Shift solenoid valve SL3
ON Malfunction (without Fail-safe Control)*
1st to 2nd
2nd
3rd
4th
5th
6th
OFF Malfunction (without Fail-safe Control)
1st
2nd to 1st
3rd
4th
5th
6th to N
Fail-safe Control during OFF Malfunction
Fixed in 3rd
Shift solenoid valve SL4
ON Malfunction (without Fail-safe Control)*
3rd
3rd
3rd
4th
5th
5th
OFF Malfunction (without Fail-safe Control)
1st
2nd
3rd to 1st
4th
5th to N
6th
Fail-safe Control during OFF Malfunction
Fixed in 2nd
  1. *: Fail-safe control is not actuated when an ON malfunction occurs.