[ Model - ECLIPSE CROSS / Year - 2018 ]
2018 / ECLIPSE CROSS / EC - Workshop Manual
35 -SERVICE BRAKES > 35C-ACTIVE STABILITY CONTROL SYSTEM (ASC) > TROUBLESHOOTING<ASC-ECU><ASC-ECU> > DIAGNOSIS CODE PROCEDURES > CODE NO. C1073: FAULTY MOTOR DRIVE CIRCUIT
Code No. C1073 Motor Drive Circuit
 
 
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
  • ASC-ECU contains the power supply circuit (+BM terminal) for the pump motor. The pump motor is energised by the motor switch, which is incorporated in ASC-ECU.
  • The pump motor switch, which is incorporated in ASC-ECU, is always off unless the motor solenoid valve check is activated when the vehicle is started.
  • ASC-ECU activates the pump motor by turning on the ECU built-in pump motor switch.
 
 
 
DIAGNOSIS CODE SET CONDITIONS
If the pump motor switch voltage drop indicates high value when the pump motor operates or after the operation, the pump motor operation is stopped and this diagnosis code is set.
 
 
 
PROBABLE CAUSES
Current trouble
  • Fusible link malfunction
  • Damaged wiring harness and connectors
  • Abnormality in battery or alternator
  • ASC-ECU malfunction
Past trouble
  • Carry out diagnosis with particular emphasis on wiring harness and connector failures between the power supply circuit (+BM terminal) to the ASC-ECU motor and the earth circuit (GND1, GND2 terminal). For diagnosis procedures, refer to How to treat past trouble (GROUP 00 - How to Use Troubleshooting/How to Treat Past Trouble ).
 
 
 
 
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-IIISE CAN bus diagnosis
Use M.U.T.-IIISE 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. Diagnosis code recheck after resetting CAN bus lines
Is diagnosis code No. C1073 set?
Go to Step 3.
This diagnosis is complete.
 
STEP 3. Battery check
Refer to GROUP 54A - Battery Test .
Is the battery in good condition?
Go to Step 4.
Replace the battery (Refer to GROUP 54A - Battery ).
 
STEP 4. Charging system check
Refer to GROUP 16 - On-vehicle Service/Alternator Output Line Voltage Drop Test .
Is the charging system in good condition?
Go to Step 5.
Repair or replace the charging system component(s) (Refer to GROUP 16 - Alternator ).
 
STEP 5. Fusible link check: Check the fusible link No.3 and No.4.
Visually check for open circuit in the fusible link No.3 and No.4.
Is the check result normal?
Go to Step 7.
Go to Step 6.
 
STEP 6. Resistance measurement at ASC-ECU connector
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Resistance between the +BM terminal and the body earth.
OK: No continuity
Is the check result normal?
Replace the fusible link No.3.
The short circuit may be present in the power supply circuit. Repair the wiring harness between the ASC-ECU connector +BM terminal and the fusible link, and then replace the fusible link No.3.
 
STEP 7. Voltage measurement at the ASC-ECU connector
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Measure the voltage between the +BM terminal and the body earth.
OK: Approximately system voltage
Is the check result normal?
Go to Step 8.
The open circuit may be present in the power supply circuit. Repair the wiring harness between the ASC-ECU connector +BM terminal and the fusible link.
 
STEP 8. Resistance measurement at ASC-ECU connector
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Resistance between the GND1 terminal and the body earth, and between the GND2 terminal and the body earth
OK: Continuity exists (2 Ω or less)
Is the check result normal?
Go to Step 9.
An open circuit may be present in the earth circuit. Repair the wiring harness between the ASC-ECU connector GND1 terminal and the body earth, and between the ASC-ECU connector GND2 terminal and the body earth.
 
STEP 9. Check whether the diagnosis code is set again.
(1) Erase the diagnosis code.
(2) Drive the vehicle at 20 km/h or higher.
noteThe ABS warning lamp does not turn OFF in some cases unless the vehicle runs at 20 km/h or higher.
Is diagnosis code No. C1073 set?
Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ).
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/How to Cope with Intermittent Malfunctions ).