[ Model - ECLIPSE CROSS / Year - 2018 ]
2018 / ECLIPSE CROSS / EC - Workshop Manual
17 -ENGINE AND EMISSION CONTROL > ADAPTIVE CRUISE CONTROL SYSTEM (ACC) > DIAGNOSIS CODE PROCEDURES > CODE NO. C1779: BRAKE MASTER CYLINDER PRESSURE SIGNAL
Code No. C1779: Brake Fluid Pressure Signal Failure
 
 
caution
  • If there is any problem in the CAN bus lines, an incorrect diagnosis code may be set. Prior to this diagnosis, diagnose the CAN bus lines.
  • Whenever the ECU is replaced, ensure that the CAN bus lines are normal.
  • When the ACC/FCM-ECU is replaced, calibrate the radar (refer to ).
 
 
OPERATION
ACC/FCM-ECU communicates with the ASC-ECU via the CAN bus lines.
 
 
DIAGNOSIS CODE SET CONDITION
Check Conditions
  • More than 2 seconds have passed since the ignition switch was turned to "ON" position.
  • ACC/FCM-ECU power voltage is more than 9 V and is less than 18 V.
Judgement Criterion
  • An abnormal brake fluid pressure signal is received from the ASC-ECU.
 
 
PROBABLE CAUSES
  • Malfunction of the CAN bus line
  • Malfunction of the ASC-ECU
  • Malfunction of ACC/FCM-ECU

 
 
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-IIISE CAN bus diagnostics.
Use M.U.T.-IIISE to perform the CAN bus diagnosis.
Is the check result normal?
Go to Step 2.
Repair the CAN bus lines (Refer to GROUP 54C - Troubleshooting, Can Bus Diagnostics Table ).
 
STEP 2. Check whether the diagnosis code is set again.
Is diagnosis code No.C1779 set?
Replace the hydraulic unit (integrated with ASC-ECU) (Refer to GROUP 35C - Hydraulic Unit ). Then go to Step 3.
It can be assumed that this malfunction is intermittent (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points, How to Cope with Intermittent Malfunction ).
 
STEP 3. Check whether the diagnosis code is set again.
Is diagnosis code No.C1779 set?
Replace the ACC/FCM-ECU (Refer to ).
This diagnosis is complete.