C1237

C1237

Component 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
With the driver torque demand and the lateral acceleration a driver braking demand is calculated. Unless the pump motor is operating or there is a brake signal, The offset compensation is executed.
A failure is detected if offset value exceeded ±15 bar.

DTC Detecting Condition:

Monitor Scantool Data
1. Connect scantool to Data Link Connector (DLC).
2. Ignition "ON" & Engine "ON".
3. Press the brake pedal.
4. Monitor the "Pressure sensor" parameter on the Scantool.

Specification: Approx. 60 bar - 150 bar (There is difference in displayed parameter according to braking force)






5. Whenever brake pedal is pushed down, is the pressure sensor's scantool 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".
3. Connect scantool and select "Diagnostic Trouble Codes (DTCs)" mode.
4. Using a scantool, 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 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 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.