Toyota Tacoma manuals

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.

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

  • *: 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 Sensor or Switch (C1254)
DESCRIPTION The accumulator pressure sensor is connected to the skid control ECU in the master cylinder solenoid. DTC No. DTC Detecting Condition Trouble Areas C1254 Accumulator pressure sensor fault (Fluid pressure does not chang ...

Short in Driver Side Squib 2nd Step Circuit (B1810/53-B1813/53)
DESCRIPTION The driver side squib 2nd step circuit consists of the airbag sensor assembly, the spiral cable with sensor sub-assembly and the horn button assembly. The circuit signals the SRS to deploy when airbag deployment conditions are met. These DTCs are set when a malfunction is detected i ...

Components
COMPONENTS ILLUSTRATION ILLUSTRATION ILLUSTRATION ILLUSTRATION ILLUSTRATION ILLUSTRATION ILLUSTRATION ILLUSTRATION ...

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