C1520
DTC C1520 Motor turning angle (input)
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 CAN Bus Diagnostics Chart ).
- Whenever ECU is replaced, ensure that the CAN bus lines are normal.
OPERATION
Power is supplied to the resolver from the EPS-ECU.
FUNCTION
To output the voltage based on the motor rotation angle to the EPS-ECU, the voltage is supplied to the resolver.
TROUBLE JUDGEMENT
Check Conditions
The power supply circuit system DTCs C1540, C1541 is not set.
Judgement 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 EPS-ECU stops the motor control and illuminates the electric power steering warning display, then sets the DTCs C1520, C1521, or C1522.
PROBABLE CAUSES
- Malfunction of CAN bus line
- Defective resolver of the steering column shaft assembly
- Defective harness wire(s) or connector(s)
- Short or open circuit between the EPS-ECU and the resolver or loose connector contact
- Malfunction of the EPS-ECU
DIAGNOSIS
STEP 1. Using scan tool MB991958, diagnose the CAN bus lines.
Use scan tool to diagnose the CAN bus lines.
Q. Is the check result normal?
YES Go to Step 3.
NO Repair the CAN bus lines CAN Bus Diagnostics Chart). 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.
Q. Is the DTCs C1520, C1521 or C1522 set?
YES Go to Step 3.
NO 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-221-1 EPS-ECU connector
Q. Is the connectors and terminals in good condition?
YES Go to Step 4.
NO Go to Step 7.
STEP 4. Wiring harness check
(1)Check the wiring harness between the C-221-1 EPS-ECU connector terminals No.21,No.22,No.23,No.25,No.27 or No.28 and the resolver for damage or other problem.
(2)Check the wiring harness between the C-222 EPS-ECU connector terminal No.12 and the body ground point for damage or other problem.
Q. Is the wiring harness in good condition?
YES Go to Step 5.
NO Go to Step 7.
STEP 5. Using scan tool MB991958, check the data list
Check the following data list Data List Reference Table.
- Item No. 04: Motor current
- Item No. 05: Motor current (target)
- Item No. 17: Motor electric angle
- Item No. 18: Motor speed
Q. Is the check result normal?
YES Go to Step 8.
NO Go to Step 6.
STEP 6. Check whether the DTC is reset.
(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.
Q. Is the DTCs C1520,C1521 or C1522 set?
YES Replace the EPS-ECU (Refer to Service and Repair).Then go to Step 7.
NO Intermittent malfunction How to Cope With Intermittent Malfunctions).
STEP 7. Check whether the DTC is reset.
(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.
Q. Is the DTCs C1520,C1521 or C1522 set?
YES Replace the steering column shaft assembly (Refer to Removal and Replacement).Then go to Step 8.
NO Intermittent malfunction How to Cope With Intermittent Malfunctions).
STEP 8. Check whether the DTC is reset.
(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.
Q. Is the DTCs C1520,C1521 or C1522 set?
YES Return to Step 1.
NO This diagnosis is complete.