Toyota Tacoma 2015-2018 Service Manual: Fail-safe Chart
FAIL-SAFE CHART
1. 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. |
|
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 |
|
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 |
||||||
- *: Fail-safe control is not actuated when an ON malfunction occurs.
Dtc Check / Clear
DTC CHECK / CLEAR
NOTICE:
When the diagnosis system is changed from normal mode to check mode or vice versa,
all DTCs and freeze frame data recorded in normal mode are cleared. Before changing
m ...
Data List / Active Test
DATA LIST / ACTIVE TEST
1. DATA LIST
HINT:
Using the Techstream to read the Data List allows the values or states of switches,
sensors, actuators and other items to be read without removing any p ...
Other materials:
Pressure Control Solenoid "C" Circuit Open (P079513)
DESCRIPTION
Changing from 1st to 6th is performed by the ECM turning shift solenoid valves
SL1, SL2, SL3 and SL4 on and off. If an open or short circuit occurs in any of the
shift solenoid valves, the ECM controls the remaining normal shift solenoid valves
to allow the vehicle to be operated ...
Compressor Lock Sensor Circuit (B1422)
SYSTEM DESCRIPTION
The ECM sends the engine speed signal to the air conditioning amplifier assembly
via CAN communication.
The air conditioning amplifier assembly reads the difference between compressor
speed and engine speed. When the difference becomes too large, the air conditioning
ampli ...
Front Speed Sensor
Removal
REMOVAL
PROCEDURE
1. PRECAUTION
NOTICE:
After turning the ignition switch off, waiting time may be required before disconnecting
the cable from the negative (-) battery terminal.
Therefore, make sure to read the disconnecting the cable from the negative (-)
battery terminal notic ...