Brake System

Component Location





General Description

Driver can inhibit the ESC control by ESC switch. When switch signal send into HECU, ESC warning lamp goes ON and ESC control is stopped and if next switch signal is inputted again, ESC control is ready. This function is used for sporty driving or vehicle inspection.

DTC Description

Trouble code is set when the condition that the level of ESC switch is high is continued for 60sec. When the ESC switch failure is set there is no signal in the warning lamp and HECU inhibits the ESC control and allows the ABS/EBD control.

DTC Detecting Condition





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
> Repair as necessary and then go to "Verification Of Vehicle Repair" procedure.
NO
> Go to "Signal Circuit Inspection" procedure.

Signal Circuit Inspection

1. Ignition "ON" & Engine "OFF" & ESC Switch "ON".
2. Measure voltage between terminal "27" of the HECU harness connector and chassis ground.

Specification : Approx B+





3. Is the measured signal waveform within specifications?
YES
> Fault is intermittent caused by open or short in ESC switch line, faulty ESC switch or was repaired and HECU memory was not cleared. Go to the applicable troubleshooting procedure.
NO
> Check for damaged harness and poor connection in the power harness between the battery terminal(+) and the terminal "27" of the HECU harness connector. Check for open or blown 10 A fuse referring to "Circuit Diagram". Repair as necessary and then go to "Verification Of Vehicle Repair" procedure.
> If OK, go to "Component Inspection" procedure.

Component Inspection

1. Ignition "OFF".
2. Disconnect ESC switch connector.
3. Press the ESC switch.
4. Measure resistance between terminal "3" of the ESC switch harness connector and terminal "4" of the ESC switch harness connector

Specification : Approx. below 1 Ohms





5. Is the measured resistance within specifications?
YES
> Fault is intermittent caused by faulty ESC switch or was repaired and HECU memory was not cleared. Go to the applicable troubleshooting procedure.
NO
> Substitute with a known-good ESC switch and check for proper operation. If problem is corrected, replace ESC switch and then 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 scantool and select "Diagnostic Trouble Codes (DTCs)" mode.
2. Using a scantool, Clear DTC.
3. Operate the vehicle within DTC Detecting Condition in General Information.
4. Are any DTCs present ?
YES
> Go to the applicable troubleshooting procedure.
NO
> System performing to specification at this time.