Code No.66: Steering Wheel Sensor Self-diagnosis Error
Code No.68: Steering Wheel Sensor Output Error


caution If there is any problem in the CAN bus lines, an incorrect diagnosis code may be set. Diagnose the CAN bus lines before the diagnosis codes (Refer to GROUP 54D, CAN bus-line diagnostic flow ).
















OPERATION


The ASTC-ECU gathers information regarding the steering operation, through the CAN bus line from the steering wheel sensor.

DIAGNOSIS CODE SET CONDITIONS


These diagnosis codes are set in the following cases:
Diagnosis code No.66
Diagnosis code No.68

PROBABLE CAUSES


The most likely causes for these diagnosis codes to set are:

DIAGNOSIS

STEP 1. M.U.T.-III CAN bus diagnostics
caution Before connecting or disconnecting the M.U.T.-III, turn the ignition switch to the "LOCK" (OFF) position.
(1)Connect M.U.T.-III to the 16-pin diagnosis connector.
(2)Turn the ignition switch to the "ON" position.
(3)Diagnose the CAN bus line.
(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the check result normal?
Go to Step 3.
Repair the CAN bus line (Refer to GROUP 54D, CAN bus line Diagnostic flow ). Then go to Step 2.

STEP 2. Check whether the diagnosis code is reset.
caution Before connecting or disconnecting the M.U.T.-III, turn the ignition switch to the "LOCK" (OFF) position.
(1)Turn the ignition switch to the "ON" position.
(2)Erase the diagnosis code.
(3)Turn the ignition switch to the "LOCK" (OFF) position.
(4)Turn the ignition switch to the "ON" position.
(5)Turn the steering wheel more than 360°.
(6)Check if the diagnosis code is set.
(7)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is code No.66 or 68 set?
Go to Step 3.
The procedure is complete.

STEP 3. Check the M.U.T.-III data list.
(1)Turn the ignition switch to the "ON" position.
(2)Start the engine.
(3)Check that the data list output changes within the following range when the steering wheel is rotated.

  • Item 32: Steering wheel operation
OK: Approximately the same value as turning angle of steering wheel is displayed

Q. Is the check result normal?
Go to Step 8.
Go to Step 4.

STEP 4. Check steering wheel sensor connector D-308, intermediate connector D-241, joint connector D-34, junction block connector D-403 and junction block connector D-405 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Is the check result normal?
Go to Step 5.
Repair or replace the damaged component(s). Then go to Step 9.

STEP 5. Check the fuses No. 12 and 18.

Q. Is the check result normal?
Go to Step 6.
Replace fuse No. 12 or 18. Then go to Step 9.

STEP 6. Check the power supply circuit at steering wheel sensor connector D-308.
(1)Disconnect steering wheel sensor connector D-308, and measure at the harness side.
(2)Turn the ignition switch to the "ON" position.
(3)Measure voltage between terminal 1 and earth.
OK: System voltage

Q. Is the check result normal?
Go to Step 7.
Repair the wiring harness between the steering wheel sensor connector D-308 and the ignition switch (IG2). Then go to Step 9.

STEP 7. Check the earth circuit at steering wheel sensor connector D-308.
(1)Disconnect steering wheel sensor connector D-308, and measure at the harness side.
(2)Measure the resistance between terminal 5 and earth.
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?
Repair the wiring harness between the steering wheel sensor connector D-308 and earth. Then go to Step 9.
Replace the steering wheel sensor. Then go to Step 8.

STEP 8. Check whether the diagnosis code is reset.
(1)Turn the ignition switch to the "ON" position.
(2)Erase the diagnosis code.
(3)Turn the ignition switch to the "LOCK" (OFF) position.
(4)Turn the ignition switch to the "ON" position.
(5)Turn the steering wheel more than 360°.
(6)Check if the diagnosis code is set.
(7)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is code No.66 or 68 set?
Replace the ASTC-ECU. Then go to Step 9.
It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction .

STEP 9. Check whether the diagnosis code is reset.
(1)Turn the ignition switch to the "ON" position.
(2)Erase the diagnosis code.
(3)Turn the ignition switch to the "LOCK" (OFF) position.
(4)Turn the ignition switch to the "ON" position.
(5)Turn the steering wheel more than 360°.
(6)Check if the diagnosis code is set.
(7)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is code No.66 or 68 set?
Repeat the troubleshooting from Step 1.
The procedure is complete.