[Previous][Next]
DTC C1531: Motor terminal voltage
 
 
caution
  • If there is any problem in the CAN bus lines, an incorrect diagnostic trouble code (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 motor from the EPS-ECU.
 
 
DIAGNOSTIC TROUBLE CODE SET CONDITION
The motor terminal voltage does not meet a predetermined voltage stored in the microcomputer, and the microcomputer determines that there is a problem in the motor terminal voltage.
 
 
PROBABLE CAUSES
  • Malfunction of CAN bus line
  • Defective motor of the steering column shaft assembly
  • Defective harness wire(s) or connector(s)
    • Short or open circuit between the EPS-ECU and the motor or loose connector contact
  • Malfunction of the EPS-ECU
 
 
DIAGNOSIS
STEP 1. Using scan tool (M.U.T.-III), diagnose the CAN bus lines.
Use scan tool (M.U.T.-III) to diagnose the CAN bus lines.
Is the check result normal?
Go to Step 3.
Repair the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ). On completion, go to Step 2.
 
STEP 2. Diagnostic trouble code recheck after resetting CAN bus lines
(1) Erase the diagnostic trouble code.
(2) Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
(3) Check if the diagnostic trouble code is set.
Is DTC C1531 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.
  • EPS-ECU connector
Is the check result normal?
Go to Step 4.
Go to Step 7.
 
STEP 4. Wiring harness check
(1) Check the wiring harness between the EPS-ECU connector terminals M+ or M- and the motor for damage or other problem.
(2) Check the wiring harness between the EPS-ECU connector terminal GND and the body ground point for damage or other problem.
Is the check result normal?
Go to Step 5.
Go to Step 7.
 
STEP 5. Using scan tool (M.U.T.-III), check data list.
Check the following data list (Refer to ).
  • Item No. 19: Motor terminal voltage (+)
  • Item No. 20: Motor terminal voltage (-)
Is the check result normal?
Go to Step 8.
Go to Step 6.
 
STEP 6. Check whether the diagnostic trouble code is set again.
(1) Erase the diagnostic trouble code.
(2) Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
(3) Check if the diagnostic trouble code is set.
Is DTC C1531 set?
Replace the EPS-ECU (Refer to ). Then go to Step 7.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points, How to Cope with Intermittent Malfunctions ).
 
STEP 7. Check whether the diagnostic trouble code is set again.
(1) Erase the diagnostic trouble code.
(2) Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
(3) Check if the diagnostic trouble code is set.
Is DTC C1531 set?
Replace the steering column shaft assembly (Refer to ). Then go to Step 8.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points, How to Cope with Intermittent Malfunctions ).
 
STEP 8. Check whether the diagnostic trouble code is set again.
(1) Erase the diagnostic trouble code.
(2) Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
(3) Check if the diagnostic trouble code is set.
Is DTC C1531 set?
Return to Step 1.
This diagnosis is complete.