Code No.C1514 Torque sensor power supply too low










caution
  • If there is any problem in the CAN bus lines, an incorrect diagnosis code may be set. Prior to this diagnosis, diagnose the CAN bus lines.
  • Whenever ECU is replaced, ensure that the CAN bus lines are normal.

OPERATION

  • Power is supplied to the torque sensor from the electric power steering-ECU.

FUNCTION

  • To output the voltage based on the input torque from the torque sensor to the electric power steering-ECU, the voltage is supplied to the torque sensor.

TROUBLE JUDGEMENT
Check Conditions
  • Torque sensor power supply ON
Judgement Criterion
  • The torque sensor power supply voltage is less than 2.5 V.
  • The torque sensor power supply monitor voltage does not meet a predetermined voltage stored in the microcomputer, and the microcomputer determines that there is a problem in the torque sensor power supply voltage.
Fail Safe, Back Up Function
  • The electric power steering-ECU stops the motor control and illuminates the electric power steering warning display, then sets the diagnosis code No. C1514.

PROBABLE CAUSES

  • Malfunction of CAN bus line
  • Defective torque sensor of the steering gear and linkage assembly
  • Defective harness wire(s) or connector(s)

    • Short or open circuit between the electric power steering-ECU and the torque sensor or loose connector contact
    • Open circuit between the body earth and the electric power steering-ECU or loose connector contact
  • Malfunction of the electric power steering-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
Use M.U.T.-III to diagnose the CAN bus lines.

Q. Is the check result normal?
Go to Step 3.
Repair the CAN bus lines (Refer to GROUP 54C - Troubleshooting ).On completion, go to Step 2.

STEP 2. Diagnosis code recheck after resetting CAN bus lines
(1)Erase the diagnosis code.
(2)Turn the ignition switch from the LOCK (OFF) position to the ON position.
(3)Check if the diagnosis code is set.

Q. Is the diagnosis codes C1514 set?
Go to Step 3.
This diagnosis is complete.

STEP 3. Check the following connector.
Check the connectors below for improper engagement, terminal damage or terminal drawn in the connector case.

  • C-113 and C-114-1 electric power steering-ECU connector
  • No.18 body earth point
  • Torque sensor intermediate connector of the wiring harness for steering gear box & linkage assembly (connection and appearance checks only)

Q. Is the connectors and terminals in good condition?
Go to Step 4.
Replace the steering gear and linkage assembly (Refer to ). Then go to Step 8.

STEP 4. Wiring harness check
(1)Check the wiring harness between the C-114-1 electric power steering-ECU connector terminals No.30 or No.31 and the torque sensor for damage or other problem .
(2)Check the wiring harness between the C-113 electric power steering-ECU connector terminal No.12 and the body earth point No.18 for damage or other problem .

Q. Is the wiring harness in good condition?
Go to Step 5.
Replace the steering gear and linkage assembly (Refer to ). Then go to Step 8.

STEP 5. Voltage measurement at the electric power steering-ECU connector

(1)The steering is in the neutral position.
(2) Measure the electric power steering-ECU voltage without disconnecting the connector (by backprobing).
(3)Turn the ignition switch from the LOCK (OFF) position to the ON position.
(4)Measure the voltage between the C-114-1 electric power steering-ECU connector terminal No.30 and No.31.
OK: 5±0.2 V

Q. Is the check result normal?

Go to Step 6.

Replace the Steering gear and linkage assembly (Refer to ).Then go to Step 8.

STEP 6. M.U.T.-III data list
(1)The steering is in the neutral position.
(2)Check the following service data .

  • Item No. 03: Torque sensor(power supply)

Q. Is the check result normal?
Go to Step 8.
Go to Step 7.

STEP 7. Check whether the diagnosis code is reset.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from the LOCK (OFF) position to the ON position.
(3)Check if the diagnosis code is set.

Q. Is the diagnosis codes C1514 set?
Replace the electric power steering-ECU (Refer to ).Then go to Step 8.
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).

STEP 8. Check whether the diagnosis code is reset.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from the LOCK (OFF) position to the ON position.
(3)Check if the diagnosis code is set.

Q. Is the diagnosis codes C1514 set?
Return to Step 1.
This diagnosis is complete.