Code No.C1534 Under real current of motor


caution
  • If the electric power steering-ECU sets diagnosis code No.C1534, diagnose the CAN bus lines. If there is any fault in the CAN bus lines, an incorrect diagnosis code may be set.
  • Whenever the ECU is replaced, ensure that the communication circuit is normal.


DIAGNOSIS CODE SET CONDITIONS

  • The motor current is less than the lower limit of the assist permission current stored in the microcomputer, but assist torque is produced. Then the microcomputer determines that there is a problem in the motor current.
    • Criteria for judging malfunction
    • Actual measurement value of the motor current (absolute value) is 1 A or less and
    • Assist torque (absolute value) is more than 0.3 N·m

PROBABLE CAUSES

  • Defective harness wire(s) or connector(s)
  • Malfunction of the electric power steering-ECU
  • Motor malfunction

DIAGNOSIS PROCEDURE

STEP 1. Check the electric power steering-ECU connector B-105-1.


  • B-105-1 electric power steering-ECU connector
Check the connectors above for improper engagement, terminal damage or terminal drawn in the connector case.

Q. Is the check result normal?

Go to Step 2.

Repair the connector(s) or terminal(s).

STEP 2. Check the motor wires of the steering gear and linkage assembly wiring harness for open circuit or voltage increase.

Disconnect electric power steering-ECU connector B-105-1 and measure the resistance.

  • Resistance between electric power steering-ECU connector B-105-1 terminals 31 and 32
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?

Go to Step 3.

Replace the steering gear box and linkage assembly (Refer to ).

STEP 3. 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.
Check again if the diagnosis code is set.
(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)Start the engine and move the steering wheel to the right and left.
(6)Check if the diagnosis code is set.
(7)Turn the ignition switch to the "LOCK" (OFF) position.
(8)Disconnect M.U.T.-III.

Q. Is diagnosis code C1534 set?

Replace the electric power steering-ECU (Refer to ).

The malfunction is intermittent. Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction .