C1237
DTC C1237 PRIMARY PRESSURE SENSOR-SIGNALCOMPONENT LOCATION:
GENERAL DESCRIPTION
The pressure sensor, installed in the HECU, sense the brake oil pressure to judge driver's brake intention when ESC is operating.
If pressure of master cylinder is applied to pressure sensor, the strain of the piezo element is changed and then the resistance of bridge circuit is changed according to changed strain.
Therefore this changed resistance changes output voltage of bridge circuit and output voltage changes linearly.
The sensor output is a analog signal in proportion to supply voltage, and the HECU recognizes a pressure value according to signal ratio about supply voltage.
DTC DESCRIPTION
The failure is detected if the pressure sensor signal noise is out of normal range, or the pressure sensor signal is changed abnormally.
In spite of no brake switch signal, master cylinder pressure exceeds 20 bar when brake switch is normal.
DTC DETECTING CONDITION:
SCHEMATIC DIAGRAM
MONITOR SCANTOOL DATA
1. Connect scan tool to Data Link Connector (DLC),
2. Ignition "ON" Engine "ON".
3. Press the brake pedal.
4. Monitor the "PRESSURE SENSOR" parameter on the scan tool.
5. Whenever brake pedal is pushed down, is the pressure sensor's scan tool data changed?
YES
Fault is caused by having been repaired and HECU memory was not cleared. Clear the DTC and then go to "Verification of Vehicle Repair" procedure.
NO
Go to "Component Inspection" procedure.
COMPONENT INSPECTION
1. Ignition "OFF".
2. Ignition "ON" Engine "OFF".
3. Connect scan tool and select "Diagnostic Trouble Codes (DTCs)" mode.
4. Using a scan tool, Clear DTC.
5. Select "Diagnostic Trouble Codes (DTCs)" mode again.
6. Are any DTCs present
YES
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
Fault is intermittent caused by faulty HECU.
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 scan tool, Clear DTC.
3. Operate the vehicle within DTC Detecting Condition in General Information.
4. Using a scan tool, Check DTC present.
5. Are any DTCs present
YES
Go to the applicable troubleshooting procedure.
NO
System performing to specification at this time.