TCS

C2380

Component Location:

General Description
The ABS HECU is composed of a ECU (Electronic Control Unit) and an HCU (Hydraulic Control Unit), so the HECU hardware includes all solenoid valves inside the unit as well as the ECU. Solenoid valves are switched to ON, OFF by HECU when the ABS is activated. Solenoid valves function is to increase, decrease or maintain the hydraulic pressure supplied to a wheel cylinder.

DTC Description
The HECU monitors the operation of the valves by checking the drive circuit of the solenoid valves, and then sets this code when the unexpected drive voltage is detected. For example, the HECU sets the DTC if an unexpected high drive voltage is detected when the valve relay is switched to OFF. (or unexpected low voltage is detected when the solenoid valve drive TR is switched to ON)

DTC Detecting Condition:

Monitor Actuation Test
1. Connect scantool to Data Link Connector (DLC)
2. Ignition "ON" & Engine "OFF".
3. Select the "Actuation Test" mode on the scantool.
4. Inspect operating status of all valves with Actuation Test.

a. Specification : It's normal if operating sound is heard.






5. Do all valves operate normally?

YES
a. 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.

NO
a. Go to "W/Harness Inspection" procedure.

Terminal and Connector Inspection
1. Many malfunctions in the electrical system are caused by poor harness(es) and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?

YES
a. Repair as necessary and then go to "Verification of Vehicle Repair" procedure.

NO
a. Go to "Component Inspection" procedure.

Component Inspection
1. Ignition "OFF".
2. Ignition "ON".
3. Connect scantool and select "Diagnostic Trouble Codes (DTCs)" mode.
4. Using a scantool, Clear DTC.
5. Operate the vehicle within DTC Detecting Condition in General Information. (Start and drive vehicle in gear and maintain vehicle speed at or above 12 km/h (7 mph).
6. Select "Diagnostic Trouble Codes (DTCs)" mode again.
7. Are any DTCs present?

YES
a. 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.

NO
a. Fault is intermittent caused by faulty HECU or was repaired and HECU memory was not cleared. go to "Verification of Vehicle Repair" procedure.

Verification of Vehicle Repair
After a repair, it is essential to verify that the fault has been corrected.
1. Connect scan tool and select "Diagnostic Trouble Codes (DTCs)" mode
2. Using a Scantool, Clear DTC.
3. Operate the vehicle within DTC Detecting Condition in General Information. (Start and drive vehicle in gear and maintain vehicle speed at or above 12 km/h (7 mph).
4. Are any DTCs present?

YES
a. Go to the applicable troubleshooting procedure.

NO
a. System performing to specification at this time.