| 1 | CHECK USING DIAGNOSTIC EQUIPMENT | ALL OK | PROBLEMS ENCOUNTERED | ACTION | 
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|  | Connect the diagnostic test equipment (Examiner or other instruments) to the tester input.Check that there are no faults in the ABS control unit. | Move on to Step 2 | 1. Error detected in the control unit | 1. Continue following the instructions for the diagnostic equipment | 
| 2. No communication with the control unit. | 2. Restore: See E7020  ABSConnection between the ABS control unit and the diagnostic connectorABS control unit supply
 | 
| 2 | ACTIVE DIAGNOSIS WITH DIAGNOSTIC EQUIPMENT | ALL OK | PROBLEMS ENCOUNTERED | ACTION | 
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|  | Connect the diagnostic equipment (Examiner or other instruments) and carry out the active diagnosis for: Pump motor;Solenoid valves.
 | Move on to Step 3 | Fault detected in the pump or in a solenoid valve. | Replace the electronic control unit electrohydraulic unit    Op. 3340A12  ABS HYDRAULIC AND ELECTRONIC CONTROL UNIT - R.R. | 
| 3 | VACUUM PIPE CHECK | ALL OK | PROBLEMS ENCOUNTERED | ACTION | 
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|  | Check that the vacuum pipe is correctly fitted/in good condition. | Move on to Step 4 | 1. Pipe not fitted correctly or bent | 1. Refit correctly | 
| 2. Pipe damaged. | 2. Replace vacuum pipeOp. 3330D24 | 
| 4 | BRAKE SERVO SINGLE-ACTING VALVE CHECK | ALL OK | PROBLEMS ENCOUNTERED | ACTION | 
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|  | Check that the brake servo single-acting valve is working properly. | Move on to Step 5 | Single-acting valve not working properly. | Clean the one-way valve if it is fouled or dirty, or else replace it.    Op. 3330D20  SINGLE-ACTING VALVE FOR BRAKE SERVO - R+R | 
| 5 | BRAKE SERVO VACUUM CHECK | ALL OK | PROBLEMS ENCOUNTERED | ACTION | 
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|  | Check the condition of the brake servo vacuum unit.Check the condition of the vacuum pipe and the connectors and bands | Move on to Step 6 | 1. Brake servo vacuum unit faulty | 1. Replace the brake servo vacuum unit.    Op. 3330D30  VACUUM PUMP - R+R | 
| 2. Pipe damaged. | 2. Renew the fastenings or replace the vacuum pipe | 
| 6 | BRAKE SERVO CHECK | ALL OK | PROBLEMS ENCOUNTERED | ACTION | 
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|  | Check that the brake servo is working properly.    See Test 3330DA CHECK VACUUM PUMP OPERATION AND BRAKE SERVO VACUUM CIRCUIT | End of diagnosis | Brake servo not working properly. | Replace brake servoOp. 3330D10 |