3308628 - F12 BRAKE PEDAL HARD

When the brake pedal is pressed, stiffness is felt during the pedal travel.
Results of the tests
1CHECKING WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Connect diagnostic equipment (Examiner or other instruments) to the diagnostic socket.

Verify:

  • that there are no faults in the ABS control unit
  • the plausibility of all the parameters
 Continue to Step 2 An error is detected in the control unitContinue following the instructions for the diagnostic equipment
Lack of dialogue with the control unit Restore the connection between the ABS control unit and diagnostic connector ( See   E7020  ABS )
2ACTIVE DIAGNOSIS WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation

Using the diagnostic equipment (Examiner or other iinstruments) carry out the active diagnosis of:

  • pump motor
  • solenoid valves
 Continue to Step 3 Pump and/or solenoids faulty Replace electrohydraulic unit-electronic control unit Op.   3340A12 
3CHECK VACUUM PIPEAll OKProblems metOperation
Check condition and fitting of vacuum pipe Continue to Step 4 Pipe fitted incorrectly or bentRefit correctly
Pipe damaged Replace the vacuum pipe Op.   3310A30 
4CHECK NON-RETURN VALVEAll OKProblems metOperation
Check that the non-return valve is working properly Continue to Step 5 Non-return valve not working properly Replace non-return valve Op.   3310A30 
5CHECK BRAKE SERVOAll OKProblems metOperation
Check that brake servo is working properly: See Test   3330DA  Check operation of brake servo Continue to Step 6 Brake servo not working properly Replace the servo unit Op. 3330D10
6CHECK ENGINE VACUUMAll OKProblems metOperation
Check vacuum in vacuum circuit: See Test   3330DA  Check operation of brake servo End of diagnosisVacuum value incorrect Replace brake servo vacuum unit Op.   3310A30 
7HECK ON CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisFault persistsSearch for the fault starting from another symptom'