Code No. C1511: Abnormal torque sensor (main)/C1512: Abnormal torque sensor (sub)









caution Before replacing ECU, ensure that the communication circuit is normal.


DIAGNOSIS CODE SET CONDITIONS



C1511: Torque sensor main system malfunction
  • The torque sensor main output voltage does not agree with the predetermined voltage stored in the microcomputer, and the microcomputer determines that a problem has occurred in the torque sensor main system.
C1512: Torque sensor sub system malfunction
  • The torque sensor sub output voltage does not agree with the predetermined voltage stored in the microcomputer, and the microcomputer determines that a problem has occurred in the torque sensor sub system.

CRITERIA FOR JUDGING MALFUNCTION


C1511: Torque sensor main system malfunction
  • The torque sensor main output voltage exceeds 4.8 V or less than 0.2 V.
C1512: Torque sensor sub system malfunction
  • The torque sensor sub output voltage exceeds 4.8 V or less than 0.2 V.

PROBABLE CAUSES


C1511: Torque sensor main system malfunction
  • Defective harness wire(s) or connector(s)
  • Defective torque sensor of the steering gear and linkage assembly
  • Malfunction of the EPS-ECU
C1512: Torque sensor sub system malfunction
  • Defective harness wire(s) or connector(s)
  • Defective torque sensor of the steering gear and linkage assembly
  • Malfunction of the EPS-ECU

DIAGNOSIS PROCEDURE


STEP 1. M.U.T.-III diagnosis code


Recheck if the diagnosis code is set.
(1)Erase the stored diagnosis code.
(2)Turn the electric motor switch to the "LOCK" (OFF) → "ON" position.
(3)Start the electric motor unit.
(4)Check if the diagnosis code is set.

Q. Is the diagnosis code, which has been set before starting the electric motor unit, still set?

Go to Step 2..
Go to Step 12..

STEP 2. M.U.T.-III diagnosis code


Recheck if the diagnosis code is set.
(1)Turn the electric motor switch to the "LOCK" (OFF) → "ON" position.
(2)Check if the diagnosis code No. C1511 and C1512 are set as the current trouble.

Q. Are the diagnosis code No. C1511 and C1512 set?

Go to Step 9..
Go to Step 3..

STEP 3. Wiring harness check between B-114-2 EPS-ECU connector terminal No. 1, 2, 3 and the torque sensor


Q. Is the check result normal?

Go to Step 4..
Repair the wiring harness.

STEP 4. M.U.T.-III data list


(1)Set the steering wheel in the straight-ahead position.
(2)Check the service data.

  • Item 01: Torque sensor main (Refer to .)
  • Item 02: Torque sensor sub (Refer to .)
  • Item 03: Torque sensor power supply voltage (Refer to .)

Q. Is the check result normal?

Go to Step 8.
Go to Step 5.

STEP 5. Voltage measurement at B-114 EPS-ECU connector


(1)Without disconnecting the connector, measure by backprobing.
(2)Measure the voltage between B-114-2 EPS-ECU connector terminal No. 1 and No. 3. (Main)
OK: Approximately 2.5 V
(3)Measure the voltage between B-114-2 EPS-ECU connector terminal No. 2 and No. 3. (Sub)
OK: Approximately 2.5 V

Q. Is the check result normal?

Go to Step 8.
Go to Step 6.

STEP 6. Measure the resistance at B-114-2 EPS-ECU connector.


(1)Disconnect the connector, and measure at the ECU side.
(2)Measure the resistance between B-114-2 EPS-ECU connector terminal No. 1 and No. 3. (Main)
OK: 0.5 to 2.0 Ω
(3)Measure the resistance between B-114-2 EPS-ECU connector terminal No. 2 and No. 3. (Sub)
OK: 0.5 to 2.0 Ω

Q. Is the check result normal?

Go to Step 7.
Replace EPS-ECU.

STEP 7. Diagnosis code recheck


Recheck if the diagnosis code is set.
(1)Turn the electric motor switch to the "LOCK" (OFF) → "ON" position.
(2)Check if the diagnosis code No. C1511 and C1512 are set as the current trouble.

Q. Are the diagnosis code No. C1511 and C1512 set?

Replace the steering gear box & linkage assembly.
Intermittent malfunction. (Refer to GROUP 00 - How to Cope with Intermittent Malfunction .)

STEP 8. Diagnosis code recheck


Recheck if the diagnosis code is set.
(1)Turn the electric motor switch to the "LOCK" (OFF) → "ON" position.
(2)Fully turn the steering wheel to both left and right.
(3)Check if the diagnosis code No. C1511 and C1512 are set as the current trouble.

Q. Are the diagnosis code No. C1511 and C1512 set?

Replace EPS-ECU.
Intermittent malfunction. (Refer to GROUP 00 - How to Cope with Intermittent Malfunction .)

STEP 9. Wiring harness check between B-114-2 EPS-ECU connector terminal No. 1, 2, 3 and the torque sensor


Q. Is the check result normal?

Go to Step 10..
Repair the wiring harness.

STEP 10. Voltage measurement at B-114-2 EPS-ECU connector


(1)Without disconnecting the connector, measure by backprobing.
(2)Turn the electric motor switch to the "ON" position.
(3)Measure the voltage between B-114-2 EPS-ECU connector terminal No. 4 and the body earth.
OK: 4.5 to 5.5 V

Q. Is the check result normal?

Go to Step 11..
Replace EPS-ECU.

STEP 11. Diagnosis code recheck


Recheck if the diagnosis code is set.
(1)Turn the electric motor switch to the "LOCK" (OFF) → "ON" position.
(2)Fully turn the steering wheel to both left and right.
(3)Check if the diagnosis code No. C1511 and C1512 are set as the current trouble.

Q. Are the diagnosis code No. C1511 and C1512 set?

Replace the steering gear box & linkage assembly.
Intermittent malfunction. (Refer to GROUP 00 - How to Cope with Intermittent Malfunction .)

STEP 12. M.U.T.-III diagnosis code


Recheck if the diagnosis code is set.
(1)Turn the electric motor switch to the "LOCK" (OFF) → "ON" position.
(2)Check if the diagnosis code No. C1514 is set.

Q. Is diagnosis code C1514 set?

Go to Step 13..
Intermittent malfunction. (Refer to GROUP 00 - How to Cope with Intermittent Malfunction .)

STEP 13. Wiring harness check between B-114-2 EPS-ECU connector terminal No. 1, 2, 3 and the torque sensor


Q. Is the check result normal?

Go to Step 14..
Repair the wiring harness.

STEP 14. STEP 14. Resistance measurement between B-114-2 EPS-ECU connector terminal No. 1 and B-114-2 EPS-ECU connector terminal No. 3


(1)Disconnect the connector, and measure at the ECU side.
(2)Measure the resistance between B-114-2 EPS-ECU connector terminal No. 1 and B-114-2 EPS-ECU connector No. 3.
OK: Continuity exists (2 Ω or less).

Q. Is the check result normal?

Go to Step 15.
Replace EPS-ECU.

STEP 15. Diagnosis code recheck


Recheck if the diagnosis code is set.
(1)Turn the electric motor switch to the "LOCK" (OFF) → "ON" position.
(2)Fully turn the steering wheel to both left and right.
(3)Check if the diagnosis code No. C1511 and C1512 are set as the current trouble.

Q. Are the diagnosis code No. C1511 and C1512 set?

Replace the steering gear box & linkage assembly.
Intermittent malfunction. (Refer to GROUP 00 - How to Cope with Intermittent Malfunction .)