Automatic Transmission System (For 2Tr-Fe) Fail-Safe Chart

Drivetrain. Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25
A343E Automatic Transmission Transaxle. Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25

  1. Fail-safe

  1. Fail-safe control list

Automatic Transmission System (For 2Tr-Fe) -- Fail-Safe Chart



Fail-safe
This function minimizes the loss of ECT functions when a malfunction occurs in a sensor or solenoid.

Fail-safe control list

Malfunctioning Part
Function
DTC P0717:
Input Speed Sensor NC0
During an input speed sensor malfunction, shift control is performed using the output speed sensor signal (SP2).
DTC P0722:
Output Speed Sensor SP2
During an output speed sensor malfunction, shift control is performed using the input speed sensor signal (NC0).
DTC P0973, P0974, P0976, P0977:
Shift Solenoid Valve S1, S2
The current to the malfunctioning solenoid valve is cut off and control is performed by operating the other normal solenoid valve.
DTC P2716:
Shift Solenoid Valve SLT
During a solenoid valve SLT malfunction, the current to the solenoid valve is stopped. This stops optimal line pressure control and shift shock increases. However, shifting is performed using normal clutch pressure control.
DTC P2769, P2770:
Shift Solenoid Valve SL
During a solenoid valve SL malfunction, the current to the solenoid valve is stopped. This stops lock-up control and fuel economy decreases.

  1. Fail-safe operation for electronically malfunctioning shift solenoid valve (S1 and S2).

    1. Fail-safe function
      If either of the shift solenoid valve circuits has an open or short failure, the ECM turns the other shift solenoid valve ON and OFF in order to shift into the gear positions shown in the table below. Also, the ECM stops sending current to the open or short-circuited solenoid.
      Even if starting the engine again in fail-safe mode, the gear position remains in the same position.

      HINT:
      X: OFF (the ECM stops sending current to the malfunctioning solenoid valve).

      Shift Solenoid Valve Electrical Malfunction
      Shift Lever Position
      		Shift Solenoid Valve S1
      		Shift Solenoid Valve S2
      		Shift Solenoid Valve S1 and S2
      Shift Solenoid Valve S1
      		Shift Solenoid Valve S2
      		Gear
      		Shift Solenoid Valve S1
      		Shift Solenoid Valve S2
      		Gear
      		Gear when Shift Lever is Manually Operated
      D
      		X
      		OFF
      		4th
      		ON
      		X
      		1st
      		4th
      X
      		ON
      		3rd
      		ON
      		X
      		1st
      		4th
      X
      		ON
      		3rd
      		OFF
      		X
      		4th
      		4th
      X
      		OFF
      		4th
      		OFF
      		X
      		4th
      		4th
      3
      		X
      		OFF
      		4th
      		ON
      		X
      		1st
      		4th
      X
      		ON
      		3rd
      		ON
      		X
      		1st
      		4th
      X
      		ON
      		3rd
      		OFF
      		X
      		4th
      		4th
      2
      		X
      		ON
      		3rd
      		ON
      		X
      		1st
      		3rd
      X
      		ON
      		3rd
      		OFF
      		X
      		3rd
      		3rd
      L
      		X
      		OFF
      		1st
      		ON
      		X
      		1st
      		1st