Toyota Tacoma 2015-2018 Service Manual: System Description
SYSTEM DESCRIPTION
1. UNLOCK OPERATION CONDITIONS FOR STEERING LOCK
(a) When the following condition is met, the unlock operation is performed.
- The engine switch is on (ACC) or on (IG).
HINT:
When the engine switch is turned on (ACC) or on (IG) and the key and certification ECU (smart key ECU assembly) are verified, the steering is unlocked.
(b) When any of the following conditions are met, key verification is performed.
- The engine switch is pressed.
- The brake pedal is depressed so that the engine can be started.
- 30 seconds have elapsed after opening and closing a door.
HINT:
- Key verification occurs when the code emitted from the key and the code stored by the certification ECU (smart key ECU assembly) are compared to check that they match.
- Certification ECU (smart key ECU assembly) verification occurs when the L code is verified while the engine is being started or the engine switch is being pushed. The steering lock ECU (steering lock actuator or UPR bracket assembly) uses the L code to determine whether the certification ECU (smart key ECU assembly) is authorized.
2. LOCK OPERATION CONDITIONS FOR STEERING LOCK
(a) When all of the following conditions are met and the certification ECU (smart key ECU assembly) has been verified, the lock operation is performed.
- The engine switch is off.
- The shift lever is in P.
- A door is opened or a door lock operation (door lock, wireless door
lock or key-linked lock operation*) is performed.
HINT:
*: This is the lock/unlock operation with the mechanical key.
3. WARNING FUNCTION
(a) A check smart key system message is displayed on the multi-information display in the combination meter assembly when one of the following occurs: 1) A vehicle speed signal malfunction is detected, 2) a malfunction that interferes with steering lock ECU (steering lock actuator or UPR bracket assembly) operation is detected.
If a malfunction occurs which results in the message being displayed, the engine cannot be started once it is turned off.
HINT:
DTCs are stored in all cases listed above.
4. STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPR BRACKET ASSEMBLY) DESCRIPTION
(a) The steering lock ECU and steering lock motor are built into the steering lock actuator assembly of the steering column assembly.
(b) The steering lock ECU (steering lock actuator or UPR bracket assembly) is not connected to the CAN communication system. However, the steering lock ECU (steering lock actuator or UPR bracket assembly) is connected to the certification ECU (smart key ECU assembly) via LIN communication and communicates with other components via CAN communication through the certification ECU (smart key ECU assembly).
Parts Location
PARTS LOCATION
ILLUSTRATION
ILLUSTRATION
...
System Diagram
SYSTEM DIAGRAM
Circuit Description
Component
Outline
Steering Lock ECU (Steering Lock Actuator or UPR Bracket Assembly)
The steering is ...
Other materials:
Open or Short in Front Speed Sensor RH Circuit (C1405,C1406)
DESCRIPTION
Refer to DTCs C1401 and C1402 (See page ).
DTC Code
DTC Detection Condition
Trouble Area
C1405
C1406
Either condition is met:
An open in the speed sensor signal circuit continues for 0.5
seconds or mor ...
Torque Converter Clutch Circuit Short to Battery or Open (P074015)
DESCRIPTION
Shift solenoid valve SL is turned on and off by signals from the ECM to control
the hydraulic pressure acting on the lock-up relay valve, which then controls operation
of the lock-up clutch.
DTC No.
DTC Detection Condition
Trouble Area
SA ...
Invalid Data Received from Deceleration Sensor (C1442,C1443)
DESCRIPTION
The skid control ECU (master cylinder solenoid) receives signals from the yaw
rate and acceleration sensor (airbag sensor assembly) via the CAN communication
system.
The airbag sensor assembly has a built-in yaw rate and acceleration sensor.
DTC Code
DTC Dete ...
