Steering Column (Except Hybrid): Overview — Toyota Highlander II (2007-2010)

SYSTEM DESCRIPTION

DESCRIPTION The steering lock system locks or unlocks the steering by activating the steering bar with a motor. The steering lock ECU activates the motor based on signals from the certification ECU (smart key ECU assembly) and main body ECU. A LIN (Local Interconnect Network) is used for communication between different ECUs in this system.
FUNCTIONS OF COMPONENTS The steering lock ECU controls the system based on information from the following components: FUNCTIONS OF COMPONENTS Item Function Steering lock actuator assembly Consists of a motor, lock bar, lock and unlock position sensors, etc. Activated by the steering lock ECU Steering lock ECU Included in the steering lock actuator assembly. This ECU activates the steering lock motor based on permission signals from the main body ECU and certification ECU (smart key ECU assembly). Detects steering lock or unlock state and transmits this status to other ECUs Main body ECU Permits the steering lock ECU to supply power to activate the motor The main body ECU and certification ECU (smart key ECU assembly) permit engine start after receiving an unlock signal from the steering lock ECU Certification ECU (Smart key ECU assembly) Orders the steering lock ECU to lock / unlock the steering. The main body ECU and certification ECU (smart key ECU assembly) permit engine start after receiving an unlock signal from the steering lock ECU IG2 relay Controlled by the main body ECU. This ECU sends IG signals to the steering lock ECU ID Code Box (Immobilizer code ECU) Transmits command to set or cancel immobilizer to the ECM based on permission signals from the certification ECU (smart key ECU assembly).

DESCRIPTION

If the steering lock ECU determines that there is a malfunction inside the ECU, it outputs this DTC. The steering lock ECU diagnosis information cannot be read directly from the steering lock ECU by the tester. The diagnosis information from the steering lock ECU is transmitted to the tester via the certification ECU (smart key ECU assembly) using the Controller Area Network (CAN).

DTC No.	DTC Detecting Condition	Trouble Area
B2781	Steering lock motor drive circuit is defective Both lock and unlock position sensors detect "ON".	Steering lock actuator assembly (Steering lock ECU)

DTC TROUBLE DETECTING CONDITION TABLE

The steering lock ECU activates the steering lock motor by the power from the main body ECU (*) through the IGE circuit. This prevents the steering from being locked while the vehicle is moving.

The diagnosis information of the steering lock ECU is transmitted to the tester via the certification ECU (smart key ECU assembly) as the steering lock ECU is not connected to the CAN communication system.

HINT

*: The power source control ECU is not a physical part. This code refers to the power source control function performed by the main body ECU.

DTC No.	DTC Detecting Condition	Trouble Area
B2782	Steering lock motor drive control circuit is defective	Wire harness Steering lock actuator assembly (Steering lock ECU) Main body ECU

DTC TROUBLE DETECTING CONDITION TABLE

Scheme 1

Scheme 1: WIRING DIAGRAM

The steering lock ECU determines the on/off status of the engine switch through the IG2 signal circuit. After receiving an IG2 relay ON signal, the steering lock ECU determines that the vehicle is moving. The steering lock ECU does not lock the steering when it receives the IG2 relay ON signal. This prevents the steering from being locked while the vehicle is moving.

DTC No.	DTC Detecting Condition	Trouble Area
B2788	Different information is obtained from IG2 signals received directly from the IG2 circuit, and from IG2 signals sent via LIN communication for a period of 1 second.	IG2 relay Wire harness Main body ECU Steering lock actuator assembly (Steering lock ECU)

DTC TROUBLE DETECTING CONDITION TABLE

Scheme 2

Scheme 2: WIRING DIAGRAM

The steering lock ECU is connected to the main body ECU and certification ECU (smart key ECU assembly). The steering lock ECU cannot activate the motor unless it receives permission signals from both ECUs. (The main body ECU permits the steering lock ECU to supply power to activate the motor.)

Scheme 3

Scheme 3: INSPECTION PROCEDURE

Scheme 4

Scheme 5

Scheme 6

Scheme 7

CHECK VEHICLE CONDITION Check the problem symptom of the steering lock system. Result RESULT TABLE Condition Proceed to Steering lock cannot be released A Steering cannot be locked B B: Go to step 6 A: Go to next step
READ VALUE USING TECH STREAM Turn the engine switch off. Connect Techstream to the DLC3. Turn the engine switch on (IG). Turn Techstream on. Enter the following menus: Body Electrical / Smart Access / Data List. Select the item below in the Data List, and read its value displayed on Techstream. Smart Access: SMART ACCESS PROCEDURE Tester Display Measurement Item/Range Normal Condition Diagnostic Note Lock/Unlock Receive Steering lock command reception record / YES or NO YES Steering lock / unlock signal received NO Steering lock / unlock signal not received - Check if a steering unlock command signal has been received. OK: "YES" is displayed on the tester display. NG: CHECK SMART KEY SYSTEM (See «HOW TO PROCEED WITH TROUBLESHOOTING»(ref-290691-S25626994292008071700000) ) OK: Go to next step
INSPECT STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU) Measure the voltage according to the value(s) in the table below. Standard voltage TESTER CONNECTION SPECIFIED CONDITION TABLE Tester Connection Switch Condition Specified Condition D11-3 (IGE) - D11-1 (GND) Engine switch off Engine switch on (ACC or IG) Motor activated: Below 1 V Motor not activated: 11 to 14 V NG: Go to step 4 OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE (See «PROBLEM SYMPTOMS TABLE»(ref-290696-S23105005872008071700000) )
CHECK HARNESS AND CONNECTOR (STEERING LOCK ACTUATOR ASSEMBLY - BODY GROUND) Disconnect the D11 connector from the steering lock actuator assembly. Measure the resistance according to the value(s) in the table below. Standard resistance TESTER CONNECTION SPECIFIED CONDITION TABLE Tester Connection Switch Condition Specified Condition D11-1 (GND) - Body ground Always Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
CHECK HARNESS AND CONNECTOR (STEERING LOCK ACTUATOR ASSEMBLY - MAIN BODY ECU) Disconnect the D8 connector from the main body ECU. Measure the resistance according to the value(s) in the table below. Standard resistance TESTER CONNECTION SPECIFIED CONDITION TABLE Tester Connection Switch Condition Specified Condition D11-3 (IGE) - D8-19 (SLR+) Always Below 1 ohms D11-3 (IGE) - Body ground Always 10 kohms or higher NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE MAIN BODY ECU
INSPECT STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU) Measure the voltage according to the value(s) in the table below. Standard voltage TESTER CONNECTION SPECIFIED CONDITION TABLE Tester Connection Condition Specified Condition D11-3 (IGE) - D11-1 (GND) The specified condition should be checked after performing the following: Move the shift lever to the N position Turn the engine switch off Open the driver's door Motor activated: Below 1 V Motor not activated: 11 to 14 V NG: Go to step 7 OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE (See «PROBLEM SYMPTOMS TABLE»(ref-290696-S23105005872008071700000) )
CHECK HARNESS AND CONNECTOR (STEERING LOCK ACTUATOR ASSEMBLY - MAIN BODY ECU) Disconnect the D11 connector from the steering lock actuator assembly. Disconnect the D8 connector from the main body ECU. Measure the resistance according to the value(s) in the table below. Standard resistance TESTER CONNECTION SPECIFIED CONDITION TABLE Tester Connection Switch Condition Specified Condition D11-3 (IGE) - D8-19 (SLR+) Always Below 1 ohms D11-3 (IGE) - Body ground Always 10 kohms or higher NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE MAIN BODY ECU

The unlock position sensor is one of the components of the steering lock actuator assembly. The sensor switch contact closes when the steering lock is released. The steering lock release signal is then sent to the main body ECU. Receiving the signal, the ECU permits engine start. (This prevents the engine from being started with the steering locked.)

Scheme 8

Scheme 8: WIRING DIAGRAM

Scheme 9

Scheme 9: INSPECTION PROCEDURE

Scheme 10

INSPECT STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU) Measure the voltage according to the value(s) in the table below. Standard voltage TESTER CONNECTION SPECIFIED CONDITION TABLE Tester Connection Switch Condition Specified Condition D11-4 (SLP1) - D11-2 (SGND) Engine switch off Engine switch on (ACC or IG) Below 1 V NG: Go to step 2 OK: CHECK SMART KEY SYSTEM (See «HOW TO PROCEED WITH TROUBLESHOOTING»(ref-290691-S25626994292008071700000) )
CHECK HARNESS AND CONNECTOR (STEERING LOCK ACTUATOR ASSEMBLY - MAIN BODY ECU) Disconnect the D11 connector from the steering lock actuator assembly. Disconnect the D8 connector from the main body ECU. Measure the resistance according to the value(s) in the table below. Standard resistance TESTER CONNECTION SPECIFIED CONDITION TABLE Tester Connection Switch Condition Specified Condition D11-4 (SLP1) - D8-18 (SLP) Always Below 1 ohms D11-4 (SLP1) - Body ground Always 10 kohms or higher NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN «PROBLEM SYMPTOMS TABLE»(ref-290696-S23105005872008071700000)

This circuit supplies voltage from the battery to terminal B of the steering lock ECU. This circuit is used as power source for the steering lock ECU, motor, communication, and peripheral circuits.

Scheme 11

Scheme 11: WIRING DIAGRAM

Scheme 12

Scheme 12: INSPECTION PROCEDURE

Scheme 13

CHECK HARNESS AND CONNECTOR (STEERING LOCK ACTUATOR ASSEMBLY - BODY GROUND) Disconnect the D11 connector from the steering lock actuator assembly. Measure the resistance according to the value(s) in the table below. Standard resistance TESTER CONNECTION SPECIFIED CONDITION TABLE Tester Connection Switch Condition Specified Condition D11-1 (GND) - Body ground Always Below 1 ohms D11-2 (SGND) - Body ground Always Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
CHECK HARNESS AND CONNECTOR (STEERING LOCK ACTUATOR ASSEMBLY - BATTERY) Measure the voltage according to the value(s) in the table below. Standard voltage TESTER CONNECTION SPECIFIED CONDITION TABLE Tester Connection Switch Condition Specified Condition D11-7 (B) - Body ground Always 11 to 14 V NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (STEERING LOCK ACTUATOR ASSEMBLY - BATTERY) OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN «PROBLEM SYMPTOMS TABLE»(ref-290696-S23105005872008071700000)