Toyota Tacoma (2015-2018) Service Manual: Fail-safe Chart
FAIL-SAFE CHART
1. FAIL SAFE OPERATION
- If there is a problem with any sensor signals or hydraulic brake booster
systems, the skid control ECU prohibits the power supply to the actuator
in the hydraulic brake booster and informs the ECM of VSC system failure.
The hydraulic brake booster turns off each solenoid and the ECM shuts off the VSC control (traction control signal) from the skid control ECU accordingly, which turns out to be as if the ABS, TRAC, A-TRAC and VSC systems were not installed.
The ABS control is prohibited, but EBD control continues as far as possible. If EBD control is impossible, the BRAKE warning light comes on to warn the driver (See page
.gif)
). - If system components have any malfunctions before starting control,
immediately stop the operation.
If system components have any malfunctions during control, gradually stop the control so as not to trigger a sudden change in vehicle conditions.
If it is impossible to control the systems, the warning light comes on to inform the driver of the termination of the systems (See page
). - VSC control continues as much as possible while the TRAC OFF indicator light is on even when the engine has failed.
HINT:
If the hydraulic brake booster encounters a malfunction, brake performance is gradually lost and ABS, BA, TRAC, A-TRAC, VSC, AUTO LSD, hill-start assist control, Crawl Control and multi-terrain select controls are prohibited.
(a) ABS, EBD and BA system:
HINT:
If the ABS, BA or EBD system malfunctions, the following controls are prohibited as shown in the table below.
|
Malfunction Area |
Control Method |
|---|---|
|
ABS system |
ABS, BA, TRAC, A-TRAC, VSC, AUTO LSD control, hill-start assist, CRAWL and multi-terrain select control are prohibited. |
|
BA system |
ABS, BA, TRAC, A-TRAC, VSC, AUTO LSD control, hill-start assist, CRAWL and multi-terrain select control are prohibited. |
|
EBD system |
ABS, BA, EBD, TRAC, A-TRAC, VSC, AUTO LSD control, hill-start assist, CRAWL and multi-terrain select control are prohibited. |
(b) TRAC, A-TRAC, VSC, AUTO LSD, hill-start assist control and CRAWL system:
HINT:
If TRAC, A-TRAC, VSC, AUTO LSD, hill-start assist control and/or CRAWL malfunction, the following controls are prohibited as shown in the table below.
|
Malfunction Area |
Control Method |
|---|---|
|
Engine control system (TRAC and A-TRAC systems) |
Before control: Disables control During control: Uses only brakes to effect control |
|
Brake control system (VSC system) |
Before control: Disables control During control: Uses only brakes to effect control |
|
Brake control system (TRAC, A-TRAC, AUTO LSD, hill-start assist control and CRAWL systems) |
Before control: Disables control During control: Disables control (by gradually ending control) |
2. SYSTEM TEMPERATURE PROTECTION OPERATION
If TRAC, A-TRAC, AUTO LSD, CRAWL or Hill-Start Assist Control system has been used constantly for a long time, the temperature of the hydraulic brake booster, may increase excessively. If the temperature increases excessively, the VSC warning buzzer sounds intermittently. If the temperature increases more, the VSC warning buzzer sounds for 3 seconds repeatedly and the indicator light either comes on or blinks.
|
System |
Indicator Condition |
|---|---|
|
TRAC, A-TRAC and hill-start assist control systems |
TRAC OFF indicator light comes on Slip indicator light comes on |
|
AUTO LSD system |
Slip indicator light comes on AUTO LSD indicator light stays on |
|
CRAWL system |
TRAC OFF indicator light comes on CRAWL indicator light blinks and then turns off |
Dtc Check / Clear
DTC CHECK / CLEAR
1. DTC CHECK / CLEAR (when Using Techstream)
(a) Check for DTCs.
(1) Connect the Techstream to the DLC3.
(2) Turn the ignition switch to ON.
(3) Turn the Techstream on.
(4) Ent ...
Freeze Frame Data
FREEZE FRAME DATA
1. FREEZE FRAME DATA
HINT:
Whenever a DTC is detected or the ABS operates, the skid control ECU
stores the current vehicle (sensor) state as freeze frame data.
The ...
Other materials:
Mechanical System Tests
MECHANICAL SYSTEM TESTS
1. STALL SPEED TEST
HINT:
This test is to check the overall performance of the engine and transmission.
CAUTION:
This test should be done on a paved surface (a surface that is not slippery).
To ensure safety, perform this test in an open and level area tha ...
Removal
REMOVAL
CAUTION / NOTICE / HINT
HINT:
When removing the name plates or stripe tapes, heat the vehicle body or tail
gate and name plates or stripe tapes using a heat light.
Heating Temperature
Item
Temperature
Vehicle Body or Tail Gate
40 to 60 ...
Terminals Of Ecu
TERMINALS OF ECU
1. CHECK 4 WHEEL DRIVE CONTROL ECU
Text in Illustration
*a
Component with harness connected
(4 Wheel Drive Control ECU)
-
-
(a) Measure the resistance and voltage according to the value(s) in the table
below.
...
