Fail-Safe Chart

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

1. ATF (Automatic Transmission Fluid) temperature sensor:

   When the ATF temperature sensor has a malfunction, O/D upshift is prohibited.

2. Counter gear speed sensor NC (Speed sensor NC): When the counter gear speed sensor has a malfunction, O/D upshift is prohibited.
3. Shift solenoid valve DSL:

   When the solenoid valve DSL has a malfunction, the current to the solenoid valve is stopped. This stops lock-up control, then fuel economy decreases.

4. Shift solenoid valve SL1, SL2 and S4:

   Fail safe function:

   If either of the shift solenoid valve circuits develops an open or short, the ECM turns the other shift solenoid "ON" and "OFF" in order to shift into the gear positions shown in the table below.

   Manual shifting as shown in the following table must be done (In case of a short circuit, the ECM stops sending the current to the short circuited solenoid). Even if starting the engine in the fail-safe mode, the gear position remains in the same position.

   HINT:

   • *1: Actual gear shift (gear position) under failsafe operation.
   • OFF: OFF (the ECM stops sending current to a malfunctioning solenoid valve)
   • →: Condition in the electrical malfunction is shown on the left of "→".

     Condition in the fail-safe mode is shown on the right of "→".

   FAIL-SAFE MODE CHART
   
   

   Normal	Solenoid Valve	SL1	ON	OFF	OFF	OFF
   		SL2	ON	ON	OFF	OFF
   		S4	OFF	OFF	OFF	ON
   	Gear Position		1st	2nd	3rd	4th (O/D)
   SL1 Malfunction	Solenoid Valve	SL1	OFF
   		SL2	ON	ON	OFF → ON	OFF → ON
   		S4	OFF	OFF	OFF → ON	ON
   	Gear Position *1		2nd	2nd	3rd	3rd
   SL2 Malfunction	Solenoid Valve	SL1	ON → OFF	OFF	OFF	OFF
   		SL2	OFF
   		S4	OFF	OFF	OFF	ON
   	Gear Position *1		3rd	3rd	3rd	4th (O/D)
   S4 Malfunction	Solenoid Valve	SL1	ON	OFF	OFF	OFF
   		SL2	ON	ON	OFF	OFF
   		SL4	OFF
   	Gear Position *1		1st	2nd	3rd	3rd
   SL1 and SL2 Malfunction	Solenoid Valve	SL1	OFF
   		SL2	OFF
   		S4	OFF	OFF	OFF	ON
   	Gear Position *1		3rd	3rd	3rd	4th (O/D)
   SL1 and S4 Malfunction	Solenoid Valve	SL1	OFF
   		SL2	ON	ON	OFF → ON	OFF → ON
   		S4	OFF
   	Gear Position *1		2nd	2nd	2nd	2nd
   SL2 and S4 Malfunction	Solenoid Valve	SL1	ON → OFF	OFF	OFF	OFF
   		SL2	OFF
   		S4	OFF
   	Gear Position *1		3rd	3rd	3rd	3rd
   SL1, SL2 and S4 Malfunction	Solenoid Valve	SL1	OFF
   		SL2	OFF
   		S4	OFF
   	Gear Position *1		3rd	3rd	3rd	3rd