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DTC C1512 Torque sensor 1, 2 excessive deviation
 
 
caution
  • If there is any problem in the CAN bus lines, an incorrect DTC may be set. Prior to this diagnosis, diagnose the CAN bus lines (Refer to GROUP 54C, CAN Bus Diagnostics Table ).
  • Whenever ECU is replaced, ensure that the CAN bus lines are normal.
 
 
OPERATION
Power is supplied to the torque sensor from the EPS-ECU.
 
 
 
FUNCTION
The voltage based on the input torque is output to the EPS-ECU from the torque sensor 1 and torque sensor 2, and the sum of the torque sensor 1 output voltage and the torque sensor 2 output voltage values are monitored for motor control.
 
 
 
TROUBLE JUDGMENT
Check Conditions
  • Engine start
Judgment Criterion
  • The sum of the torque sensor 1 output voltage and the torque sensor 2 output voltage does not meet a predetermined value stored in the microcomputer, and the microcomputer determines that a problem has occurred in the mutual monitoring for the sensor 1/2 systems.
Fail Safe, Back Up Function
  • The EPS-ECU stops the motor control and illuminates the electric power steering warning display, then sets DTC C1512.
 
 
 
TROUBLESHOOTING HINTS
  • Defective torque sensor of the steering column shaft assembly
  • Defective harness wire(s) or connector(s)
  • Malfunction of the EPS-ECU
 
 
 
 
DIAGNOSIS
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Using scan tool (M.U.T.-IIISE), check the data list.
(1)
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-IIISE).
Connect scan tool (M.U.T.-IIISE). Refer to "How to Connect the Scan Tool (M.U.T.-IIISE) ."
(2) The steering is in the neutral position.
(3) Check the following data list (Refer to ).
  • Item No. 01: Torque sensor voltage1
  • Item No. 02: Torque sensor voltage2
Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunctions ).
Go to Step 2.
 
STEP 2. Voltage measurement at EPS-ECU connector (TRQ1, TRQ2, TRQG1, TRQG2 terminal)
(1) The steering is in the neutral position.
(2) Measure the EPS-ECU voltage without disconnecting the connector (by backprobing).
(3) Engine start
(4) Measure the voltage between the EPS-ECU connector (TRQ1 terminal) and the EPS-ECU connector (TRQG1 terminal) or body ground. <Torque sensor 1 system>
OK: 2.5 ± 0.05 volts
(5) Measure the voltage between the EPS-ECU connector (TRQ2 terminal) and the EPS-ECU connector (TRQG2 terminal) or body ground. <Torque sensor 2 system>
OK: 2.5 ± 0.05 volts
Is the check result normal?
Go to Step 4.
Replace the steering column shaft assembly (Refer to ). Then go to Step 3.
 
STEP 3. Using scan tool (M.U.T.-IIISE), check whether the DTC is set again.
(1) Erase the DTC.
(2) Engine start
(3) Check if the DTC is set.
Is the DTC set?
Replace the EPS-ECU (Refer to ).
This diagnosis is complete.
 
STEP 4. Using scan tool (M.U.T.-IIISE), check whether the DTC is set again.
(1) Erase the DTC.
(2) Engine start
(3) Check if the DTC is set.
Is the DTC set?
Replace the EPS-ECU (Refer to ).
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunctions ).