Toyota 4Runner: 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
.gif)
).
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 | .gif) |
GO TO SMART KEY SYSTEM (FOR START FUNCTION) (PROBLEM SYMPTOMS TABLE) |
|
.gif)
|
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 |
|
|
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 |
|
*a |
Front view of wire harness connector (to Steering Lock ECU) |
| NG | |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
4. |
INSPECT STEERING LOCK ECU (IGE VOLTAGE) |
|
(a) Move the shift lever to P. |
|
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(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 |
|
*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 |
|
|
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 |
|
|
7. |
REPLACE STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU) |
(a) Replace the steering lock actuator assembly (steering lock ECU) (See page
).
|
|
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 ).
|
|
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 ).
|
|
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 ...
Steering System
...
Other materials about Toyota 4Runner:
Front Wiper Rubber
Components
COMPONENTS
ILLUSTRATION
Replacement
REPLACEMENT
CAUTION / NOTICE / HINT
HINT:
Use the same procedure for the RH and LH sides.
The procedure listed below is for the LH side.
PROCEDURE
1. REMOVE FRONT WIPER BLADE
(a) ...
How To Proceed With Troubleshooting
HOW TO PROCEED WITH TROUBLESHOOTING
1. OPERATION FLOW
HINT:
Perform troubleshooting in accordance with the procedures below. The following
is an outline of basic troubleshooting procedures. Confirm the troubleshooting procedures
for the circuit you are ...
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