Code No.C1530
Motor FET driver Code No.C1531 Motor current too low Code No.C1532 Motor output
current too large Code No.C1533 Motor terminal initial voltage Code No.C1534
Motor terminal monitor voltage Code No.C1535 Motor output current Code No.C1536
Motor terminal voltage too high
caution
If there is
any problem in the CAN bus lines, an incorrect diagnosis code 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.
FUNCTION
The voltage controlled by the torque sensor and resolver is supplied to the motor from
the EPS-ECU.
TROUBLE JUDGEMENT
Check Conditions
The battery voltage is more than 8 V or less than 17 V.
Judgement Criterion
The motor voltage does not meet a predetermined voltage stored in the microcomputer,
and the microcomputer determines that there is a problem in the motor system.
Fail Safe, Back Up Function
The EPS-ECU stops the motor control and illuminates the electric power steering
warning display, then sets the diagnosis code No. C1530, C1531, C1532, C1533, C1534, C1535,
and C1536.
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
Open circuit between the body earth and the EPS-ECU or loose connector contact
Malfunction of the EPS-ECU
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use M.U.T.-III to diagnose the CAN bus lines.
Q.
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. Diagnosis code recheck after resetting CAN bus lines
(1)Erase the diagnosis code.
(2)Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
(3)Check if the diagnosis code is set.
Q.
Is the diagnosis codes C1530,C1531,C1532,C1533,C1534,C1535 or C1536 set?
Go to Step 3.
This diagnosis is complete.
STEP 3. Check of short to power supply, short to earth, and open circuit
in V, W, U line between EPS-ECU connector and motor
Q.
Is the check result normal?
Go to Step 4.
Go to Step 7.
STEP 4. Check of open circuit in GND line between EPS-ECU connector
and body earth connector
Q.
Is the check result normal?
Go to Step 5.
Go to Step 7.
STEP 5. M.U.T.-III data list
Check the following data list .
Item No. 04: Motor current
Item No. 05: Motor current (target)
Item No. 06: Motor current (unlimited target)
Item No. 17: Motor electric angle
Item No. 18: Motor speed
Item No. 19: Motor voltage
Item No. 25: Motor relay
Q.
Is the check result normal?
Go to Step 8.
Go to Step 6.
STEP 6. Check whether the diagnosis code is reset.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
(3)Check if the diagnosis code is set.
Q.
Is the diagnosis codes C1530,C1531,C1532,C1533,C1534,C1535 or C1536 set?
Replace the EPS-ECU (Refer to ).Then go to
Step 7.
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent
Malfunctions ).
STEP 7. Check whether the diagnosis code is reset.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
(3)Check if the diagnosis code is set.
Q.
Is the diagnosis codes C1530,C1531,C1532,C1533,C1534,C1535 or C1536 set?
Replace the steering column shaft assembly (Refer to ).Then
go to Step 8.
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent
Malfunctions ).
STEP 8. Check whether the diagnosis code is reset.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
(3)Check if the diagnosis code is set.
Q.
Is the diagnosis codes C1530,C1531,C1532,C1533,C1534,C1535 or C1536 set?
Go to Step 3.
Repair the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table 
).
On completion, go to Step 2.