Toyota Tacoma (2015-2018) Service Manual: System Diagram

Toyota Tacoma (2015-2018) Service Manual / Steering Column / Steering Lock System / System Diagram

SYSTEM DIAGRAM

Circuit Description

Component	Outline
Steering Lock ECU (Steering Lock Actuator or UPR Bracket Assembly)	The steering is locked and unlocked by communicating with the certification ECU (smart key ECU assembly) via LIN communication. When the following conditions are met, the steering can be unlocked. The codes (L codes) of the certification ECU (smart key ECU assembly) and steering lock match. The certification ECU (smart key ECU assembly) and key ID codes match.
Certification ECU (Smart Key ECU Assembly)	The ID code of the key the user is carrying is sent to the electrical key antenna. The certification ECU (smart key ECU assembly) compares the key ID code it receives from the electrical key antenna with its own ID code. If they match, the certification ECU (smart key ECU assembly) permits the steering lock ECU (steering lock actuator or UPR bracket assembly) to turn the power on, start the engine and unlock and lock the steering. Outputs a command to supply power to the steering lock motor based on the power source mode, shift position and vehicle speed signal.

Component

Outline

Steering Lock ECU (Steering Lock Actuator or UPR Bracket Assembly)

The steering is locked and unlocked by communicating with the certification ECU (smart key ECU assembly) via LIN communication.
When the following conditions are met, the steering can be unlocked.
- The codes (L codes) of the certification ECU (smart key ECU assembly) and steering lock match.
- The certification ECU (smart key ECU assembly) and key ID codes match.

Certification ECU (Smart Key ECU Assembly)

The ID code of the key the user is carrying is sent to the electrical key antenna.
The certification ECU (smart key ECU assembly) compares the key ID code it receives from the electrical key antenna with its own ID code. If they match, the certification ECU (smart key ECU assembly) permits the steering lock ECU (steering lock actuator or UPR bracket assembly) to turn the power on, start the engine and unlock and lock the steering.
Outputs a command to supply power to the steering lock motor based on the power source mode, shift position and vehicle speed signal.

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). H ...

How To Proceed With Troubleshooting

CAUTION / NOTICE / HINT HINT: Use the following procedures to troubleshoot the steering lock system. *: Use the Techstream. PROCEDURE 1. VEHICLE BROUGHT ...

Other materials:

Fail-safe Chart
FAIL-SAFE CHART 1. FAIL-SAFE FUNCTION (a) When communication fails in any of the CAN bus lines (communication lines), a fail-safe function(s) will operate. The fail-safe function that is specified for each system operates to prevent those systems from malfunctioning. (b) The following table s ...

Diagnosis System
DIAGNOSIS SYSTEM 1. DESCRIPTION (a) Smart key system (for start function) data and the Diagnostic Trouble Codes (DTCs) can be read through the Data Link Connector 3 (DLC3) of the vehicle. When the system seems to be malfunctioning, use the Techstream to check for malfunctions and perform rep ...

Transmission Fluid Temperature Sensor "B" Circuit Short to Battery or Open (P274015)
DESCRIPTION The No. 2 ATF temperature sensor is installed in the transmission valve body assembly. If the ECM detects an abnormally high ATF temperature near this sensor, it illuminates the warning indicator. HINT: The temperature of ATF easily rises when towing, climbing hills, in traffic, ...