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:
How To Proceed With Troubleshooting
CAUTION / NOTICE / HINT
HINT:
Use the following procedure listed to troubleshoot the differential
system (w/ Differential Lock).
*: Use the Techstream.
PROCEDURE
1.
VEHICLE BROUGHT TO WORKSHOP
NEXT
...
Tire Pressure Monitor ECU Communication Stop Mode
DESCRIPTION
Detection Item
Symptom
Trouble Area
Tire Pressure Monitor ECU Communication Stop Mode
Either condition is met:
Communication stop for "Tire Pressure2" is indicated on the
"Communication Bus C ...
Black Screen
PROCEDURE
1.
CHECK DISPLAY SETTING
(a) Check that the display is not in "Screen Off" mode.
OK:
The display setting is not in "Screen Off" mode.
NG
CHANGE SCREEN TO SCREEN ON MODE
OK
...
