C1503

C1503

Component Location:

General Description
Driver can inhibit the TCS control by TCS switch. When switch signal send into HECU, TCS warning lamp go ON and TCS control is stopped and if next switch signal is inputted again, TCS 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 TCS switch is high is continued for 60 sec.When the TCS switch failure is set there is no signal in the warning lamp and HECU inhibit the TCS control and allow the ABS/EBD control.

DTC Detecting Condition:

Schematic Diagram:

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 "Signal Circuit Inspection" procedure.

Signal Circuit Inspection
1. Ignition "ON" & Engine "OFF" & TCS Switch"ON".
2. Measure voltage between terminal "14" of the HECU harness connector and chassis ground.

a. Specification : Approx. B+






3. Is the measured voltage within specifications?

YES
a. Go to "Component Inspection" Procedure.

NO
a. Check for damaged harness and poor connection in the power harness between the battery terminal (+) and the terminal "14" 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.
b. If OK, Go to "Component Inspection" Procedure.

Component Inspection
1. Ignition "OFF".
2. Disconnect TCS switch connector.
3. Measure resistance between terminal "3" of the TCS switch component connector and terminal "4" of the TCS switch component connector.

a. Specification : Approx. below 1 ohm






4. Is the measured resistance within specifications?

YES
a. Fault is intermittent caused by poor connection in TCS switch line or was repaired and HECU memory was not cleared. Go to "Verification of Vehicle Repair" procedure.

NO
a. Substitute with a known-good TCS switch and check for proper operation. If problem is corrected, replace TCS 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 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.
4. Are any DTCs present?

YES
a. Go to the applicable troubleshooting procedure.

NO
a. System performing to specification at this time.