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
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). - 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:
Check Mode Procedure
CHECK MODE PROCEDURE
1. DESCRIPTION
Check mode has a higher sensitivity to malfunctions and can detect malfunctions
that cannot be detected in normal mode. Check mode can also detect all of the malfunctions
that can be detected in normal mode. In check mode, DTCs are stored with 1 trip
detec ...
Sound Signal Circuit between Radio Receiver and Stereo Component Amplifier
DESCRIPTION
The navigation receiver assembly sends a sound signal to the stereo component
amplifier assembly via this circuit.
The sound signal that has been sent is amplified by the stereo component amplifier
assembly, and then is sent to the speakers.
If there is an open or short in the cir ...
Transmitter ID1 Operation Stop (C2111/11-C2114/14)
DESCRIPTION
The tire pressure warning valve and transmitters that are installed in the tire
and wheel assemblies measure the tire pressure of each wheel. The measured values
are transmitted to the tire pressure warning ECU and receiver in the vehicle as
radio waves. The ECU compares the measu ...