C1112

C1112

Component Location:

General Description
The HECU supplies operating voltage with pressure sensor, Yaw & later G sensor.
The HECU monitors supply voltage of each sensor for normal ESC control.
If supply voltage is out of specified range TCS/ESC warning lamps are turned on and TCS/ESC controls are inhibited.

DTC Description
A failure is detected if the external sensor supply voltage is out of the specified range for more than the specified min. fault duration.

DTC Detecting Condition:

Schematic Diagram:

Monitor Scantool Data
1. Connect scantool to Data Link Connector (DLC)
2. Ignition "ON" & Engine "ON".
3. Maintain the vehicle standing still.
4. Monitor the "5 VOLT REFERENCE" parameter on the Scantool.

Specification : Approx. 5 V






5. Is parameter displayed within specifications?

YES
a. Fault is intermittent caused by poor connection in 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 "Component 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 "Power Circuit Inspection" procedure.

Power Supply Circuit Inspection
1. Ignition "ON" & Engine "OFF".
2. Measure voltage between terminal "3" of the Yaw Rate & Lateral G sensor harness connector and chassis ground.

Specification : Approx. 5 V






3. Is the measured voltage within specifications?

YES
a. Go to number 4 (Power Circuit Inspection procedure of pressure sensor).

NO
a. Check for short to GND or short to B+ in the Yaw Rate & Lateral G sensor harness between terminal "3" of the Yaw Rate & Lateral G sensor harness connector and terminal "36" of the HECU harness connector. Repair as necessary and then go to "Verification of vehicle Repair" procedure. If OK, go to "Component Inspection" procedure.

4. Measure voltage between terminal "2" of the pressure sensor harness connector and chassis ground.

Specification : Approx. 5 V






5. Is the measured voltage within specifications?

YES
a. Go to "Component Inspection" procedure.

NO
a. Check for short to GND or short to B+ in pressure sensor harness between terminal "2" of the pressure sensor harness connector and terminal "37" of the HECU harness connector. Repair as necessary 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.