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.
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 ...
Diagnostic Trouble Code Chart
DIAGNOSTIC TROUBLE CODE CHART
If a DTC is displayed during the DTC check, check the parts listed in
the table below and proceed to the "See page" given.
*1: "Comes on&qu ...
Other materials:
Pressure Control Solenoid "A" Performance (Shift Solenoid Valve SL1) (P0746)
SYSTEM DESCRIPTION
The ECM uses the vehicle speed signal and signals from the transmission revolution
sensors (NT, SP2) to detect the actual gear (1st, 2nd, 3rd, 4th, 5th or 6th gear).
The ECM compares the actual gear with the shift schedule in the ECM memory to
detect mechanical problems of t ...
Terminals Of Ecu
TERMINALS OF ECU
1. CHECK DRIVER SIDE JUNCTION BLOCK AND MAIN BODY ECU (MULTIPLEX NETWORK BODY
ECU)
(a) Disconnect the MB main body ECU (multiplex network body ECU) connectors.
(b) Measure the voltage and resistance according to the value(s) in the table
below.
HINT:
Measure the values on ...
Removal
REMOVAL
PROCEDURE
1. REMOVE REFRIGERANT FROM REFRIGERATION SYSTEM
2. REMOVE AIR CONDITIONER PRESSURE SENSOR
(a) Disconnect the connector.
(b) Using a 27 mm deep socket wrench, remove the air conditioner pressure
sensor.
T ...
