4.
Inspect operating status of Motor with Actuation Test.
Specification : It's normal if operating sound is heard.
Fig 1) Test Condition : Ignition "ON" & Engine "OFF".
Ex) Actuation Test on Motor
The ABS ECU supplies battery power to the electric motor by way of a motor relay which is controlled by the Electronic Control Unit(ECU).
The electric motor pump supplies hydraulic pressure to all wheel brake calipers by operating the piston inside the pump.
The ABS ECU monitors the pump motor relay or fuse open, open or short in motor or motor lock and then sets this code if a malfunction is detected.
Item | Detecting Condition | Possible cause | |
DTC Strategy | ● Battery Voltage Monitoring | ● Open or short of power supply circuit (ABS1) ● Faulty HECU | |
Case1 (Motor Relay Open orMotor Short to GND) | Enable Conditions | ● If the motor relay is switched ON and motor voltage < (IGN voltage – 4V±0.5V) continued for 49msec, the failure is detected. | |
Case2 (Motor Lock) | Enable Conditions | ● After motor relay is switched OFF, VMR is measured. If the time which VMR > 1±0.1V is less than evaluation time, recheck is performed again for a maximum of three times. When VMR is not normal even on the third recheck, the controller recognizes it as failure. | |
Case3 (Motor Open, Motor Short to BATT) | Enable Conditions | ● After 1.8sec from the time that motor relay is switched OFF, VMR > 4±0.5V continued for 1.8sec, the failure is detected. | |
Case4 (Motor Fuse Open) | Enable Conditions | ● If the motor relay is switched OFF and VMRP (Motor power supply voltage) < 4±0.5V continued for 1sec, the failure is detected. | |
Fail Safe | ● ABS/ESP functions are inhibited, EBD function is allowed and the ABS/ESP warning lamps are activated. | ||
Connect scantool to Data Link Connector(DLC)
Ignition "ON" & Engine "OFF".
Select the "Actuation Test" mode on the scantool.
Inspect operating status of Motor with Actuation Test.
Specification : It's normal if operating sound is heard.
Fig 1) Test Condition : Ignition "ON" & Engine "OFF".
Ex) Actuation Test on Motor
Do all valves operate normally?
 | ▶ Fault is intermittent caused by poor connection in power harness (ABS1) and/or HECU's connector or was repaired and HECU memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure. |
 | ▶ Go to "Terminal and Connector Inspection" procedure. |
Many malfunctions in the electrical system are caused by poor harness(es) and terminal condition. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
Has a problem been found?
| ▶ Repair as necessary and then go to "Verification of Vehicle Repair" procedure. |
| ▶ Go to "Power Circuit Inspection" procedure. |
Ignition "ON" & Engine "OFF".
Measure voltage between power(ABS1) terminal of the HECU harness connector and chassis ground.
Specification : B+
Is the measured value within specifications?
| ▶ Go to "Ground Circuit Inspection" procedure. |
| ▶ Check for open or blown 40A (ABS1) fuse referring to "Circuit Diagram". Repair open or short in power circuit between battery and HECU harness connector and then, go to "Verification of vehicle Repair" procedure. |
Ignition "OFF" & Engine "OFF".
Disconnect the HECU connector.
Measure resistance between ground terminal of the HECU harness connector and chassis ground.
Specification : Approx. below 1Ω
Is the measured value within specifications?
| ▶ Substitute with a known-good HECU and check for proper operation. If problem is corrected, replace HECU and then go to "Verification of Vehicle Repair" procedure. |
| ▶ Repair open or short in ground circuit between HECU harness connector and chassis ground, and then go to "Verification of vehicle Repair" procedure. |
After a repair, it is essential to verify that the fault has been corrected.
Connect scantool and select "Diagnostic Trouble Codes(DTCs)" mode
Using a scantool, Clear DTC.
Operate the vehicle within DTC Detecting Condition in General Information. (Start and drive vehicle in gear and maintain vehicle speed at or above 12kmh. (7.5mph)
Using a scantool, Check DTC present.
Are any DTCs present ?
| ▶ Go to the applicable troubleshooting procedure. |
| ▶ System performing to specification at this time. |
