323001752 - F021 ABS NOT WORKING / (ONE WHEEL LOCKED)

When the brakes are operated briskly and suddenly (emergency braking) the ABS does not work and, as a result, one of the wheels locks
The locking of one of the wheels may, in certain circumstances, be a normal reaction of the system (see operation of the ABS system). This is possible, in particular, on uneven roads
TEST RESULTS
1CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
Connect the Examiner diagnostic equipment to the diagnostic socket.Check:- that there are no errors in the ABS control unit;- the plausibility of all the parametersMove on to Step 21. Error detected in the control unit.2. No communication with the control unit.1. Continue following the instructions on the diagnostic equipment2. Restore connection between the ABS control unit and the diagnostic connector    See E7020 ABS
2ACTIVE DIAGNOSIS WITH DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
Keeping the Examiner diagnostic equipment connected, carry out the active diagnosis of:- pump motor;- solenoid valves.Move on to Step 3Fault detected in one of the solenoid valves.Replace the electrohydraulic unit - ABS electronic control unit    Op. 3340A12 ABS HYDRAULIC AND ELECTRONIC CONTROL UNIT - R.R.
3AIR PRESENCE CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Check for the presence of air in the systemMove on to Step 4Air in the system.Bleed the air from the system    Op. 0010T65 HYDRAULIC BRAKE SYSTEM - BLEED AIR
4PIPE / HOSE AND BRAKE BLEEDING CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Visually inspect that there are no bends or constrictions in the brake pipes.Move on to Step 5Presence of bends or constrictions.Replace the section of pipe affected by the problem.
5BRAKE CALLIPER CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Check the sliding of the brake calliper control pistons.Move on to Step 6Front calliper pistons seized.Replace the front brake callipers    Op. 3310A30 FRONT BRAKE CALIPER (ONE) - R.R
6REAR BRAKE SHOE CONTROL CYLINDER CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Check that the rear drum brake shoe control cylinders are working properly.End of diagnosisShoe control cylinders not working properly.Replace the cylinders    Op. 3320B20 REAR BRAKE SHOE CYLINDER (ONE) LEFT OR RIGHT - REPLACE.