Toyota 4Runner manuals

Toyota 4Runner: Unable to Unlock Steering Wheel (Engine cannot Start)

Toyota 4Runner Service Manual / Steering / Steering Column / Steering Lock System / Unable to Unlock Steering Wheel (Engine cannot Start)

DESCRIPTION

The power management control ECU supplies the power to activate the motor of the steering lock actuator assembly.

The steering lock actuator activates the steering lock motor and moves the lock bar into the steering column to lock the steering wheel.

The steering lock may not release when the lock bar gets stuck in the lock hole of the steering column. In this case, if an engine start operation is performed while shaking the steering wheel in the same manner as is done for a vehicle with a mechanical key, the lock bar will release.

The diagnosis information of the steering lock ECU is transmitted to the Techstream via the certification ECU as the steering lock ECU is not connected to the CAN communication system.

WIRING DIAGRAM


CAUTION / NOTICE / HINT

HINT:

When the engine switch is off, the main body ECU may occasionally go into a non-active state called sleep mode. Therefore, before proceeding with the inspection, it is necessary to perform the following steps to wake up the ECU:

With the engine switch off, open the driver door. Then (with the engine switch still off) open and close any door several times at 1.5 second intervals.

NOTICE:

  • If the steering lock actuator assembly (steering lock ECU) is replaced, with the engine switch off and the shift lever in P, open and close the driver side door to record the current lock position into the steering lock ECU. If this is not performed, the engine may not start.
  • When replacing the steering lock ECU, ID code box or certification ECU, registration must be performed (See page
    ).

PROCEDURE

1.

CHECK ENGINE SWITCH (SWITCH CONDITION)

(a) Check the power source mode change.

(1) When the key is inside the vehicle and the shift lever is in P, check that pressing the engine switch causes the power source mode to change as follows:

OK:

off → on (ACC) → on (IG) → off


NG

GO TO SMART KEY SYSTEM (FOR START FUNCTION) (PROBLEM SYMPTOMS TABLE)


OK

2.

READ VALUE USING TECHSTREAM (UNLOCK REQUEST RECEIVE)

(a) Use the Data List to check if the steering lock command is functioning properly.

Smart Key

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

Unlock Request Receive

Steering lock unlock command reception status/NG or OK

NG: Unlock request not received

OK: Unlock request received

-

OK:

The certification ECU receives an unlock request signal within 10 seconds of starting the engine, and OK is displayed on the Techstream screen.


NG

GO TO STEP 5


OK

3.

CHECK HARNESS AND CONNECTOR (STEERING LOCK ECU - BATTERY AND BODY GROUND)

(a) Disconnect the F68 steering lock ECU connector.


(b) Measure the resistance and voltage according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

F68-1 (GND) - Body ground

Always

Below 1 Ω

Standard Voltage:

Tester Connection

Condition

Specified Condition

F68-7 (B) - Body ground

Always

11 to 14 V

Text in Illustration

*a

Front view of wire harness connector

(to Steering Lock ECU)


NG

REPAIR OR REPLACE HARNESS OR CONNECTOR


OK

4.

INSPECT STEERING LOCK ECU (IGE VOLTAGE)

(a) Move the shift lever to P.


(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

F68-3 (IGE) - F68-1 (GND)

Steering lock motor operating immediately after turning engine switch from off to on (IG)

Below 1 V

F68-3 (IGE) - F68-1 (GND)

Steering lock motor not operating

11 to 14 V

Text in Illustration

*a

Component with harness connected

(Steering Lock ECU)


OK

REPLACE STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU)


NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.

READ VALUE USING TECHSTREAM (S CODE CHECK)

(a) Use the Data List to check if the S code certification is functioning properly.

Smart Key

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

S Code Check

S code certification result/NG or OK

OK: S code certification result normal

NG: S code certification result abnormal

-

OK:

OK is displayed on the Techstream.


NG

GO TO STEP 9


OK

6.

READ VALUE USING TECHSTREAM (L CODE CHECK)

(a) Use the Data List to check if the L code certification is functioning properly.

Smart Key

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

L Code Check

L code certification result/NG or OK

OK: L code certification result normal

NG: L code certification result abnormal

-

OK:

OK is displayed on the Techstream.


NG

GO TO STEP 11


OK

7.

REPLACE STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU)

(a) Replace the steering lock actuator assembly (steering lock ECU) (See page ).



NEXT

8.

CHECK STEERING LOCK RELEASE OPERATION

(a) Turn the engine switch on (IG).

(b) Operate the steering wheel and check the steering lock condition.

OK:

Steering lock is released.


OK

END (STEERING LOCK ECU IS DEFECTIVE)


NG

REPLACE CERTIFICATION ECU

9.

REPLACE ID CODE BOX

(a) Replace the ID code box (See page ).



NEXT

10.

READ VALUE USING TECHSTREAM (S CODE CHECK)

(a) Use the Data List to check if the S code certification is functioning properly.

Smart Key

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

S Code Check

S code certification result/NG or OK

OK: S code certification result normal

NG: S code certification result abnormal

-

OK:

OK is displayed on the Techstream.


OK

END (ID CODE BOX IS DEFECTIVE)


NG

REPLACE CERTIFICATION ECU

11.

REPLACE ID CODE BOX

(a) Replace the ID code box (See page ).



NEXT

12.

READ VALUE USING TECHSTREAM (L CODE CHECK)

(a) Use the Data List to check if the L code certification is functioning properly.

Smart Key

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

L Code Check

L code certification result/NG or OK

OK: L code certification result normal

NG: L code certification result abnormal

-

OK:

OK is displayed on the Techstream.


OK

END (ID CODE BOX IS DEFECTIVE)


NG

REPLACE STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU)

Unable to Lock Steering Wheel
DESCRIPTION The steering lock ECU sends an unlock position signal to the power management control ECU. Upon receiving the signal, the power management control ECU permits an engine start. This pr ...

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