DTC C1521 Motor turning angle (output) DTC C1522 Motor turning angle range
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 resolver from the electric power steering-ECU.
FUNCTION
To output the voltage based on the motor rotation angle to the electric power steering-ECU, the voltage is supplied to the resolver.
TROUBLE JUDGMENT
Check Conditions
The power supply circuit system DTC C1540, C1541 is not set.
Judgment Criterion
The resolver input voltage or the resolver output voltage does not meet a predetermined voltage stored in the microcomputer, and the microcomputer determines that there is a problem in the resolver system.
Fail Safe, Back Up Function
The electric power steering-ECU stops the motor control and illuminates the electric power steering warning symbol, then sets DTC C1521, or C1522.
PROBABLE CAUSES
Malfunction of CAN bus line
Defective resolver of the steering column shaft assembly
Malfunction of the electric power steering-ECU
DIAGNOSIS
STEP 1. Using scan tool MB991958, diagnose the CAN bus lines.
Use scan tool to diagnose the CAN bus lines.
Is the check result normal?
Go to Step 3.
Repair the CAN bus lines (Refer to GROUP 54C - Diagnosis/CAN Bus Diagnostics Table ). On completion, go to Step 2.
STEP 2. DTC recheck after resetting CAN bus lines
(1) Erase the DTC.
(2) Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
(3) Check if the DTC is set.
Is DTC C1521 or C1522 set?
Go to Step 3.
This diagnosis is complete.
STEP 3. Using scan tool MB991958, check the data list
Check the following data list .
Item No. 04: Motor current
Item No. 05: Motor current (target)
Item No. 17: Motor electric angle
Item No. 18: Motor speed
Is the check result normal?
Go to Step 5.
Go to Step 4.
STEP 4. Check whether the DTC is set again.
(1) Erase the DTC.
(2) Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
(3) Check if the DTC is set.
Is DTC C1521 or C1522 set?
Replace the electric power steering-ECU (Refer to ).Then go to Step 5.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/How to Cope with Intermittent Malfunctions ).
STEP 5. Check whether the DTC is set again.
(1) Erase the DTC.
(2) Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.