421 

 

Inspection items 

Key switch gear Operation 

Standard 

value 

Remark 

Note: there must have the vacuum acting on the vacuum booster when the following inspections are made. 

ON Pedal 

The pedal does not go down 

when the left front wheel is 

incapable of rotating 

Inspection to the normally 

closed valve 

Tightness of left front 

wheel normally open 

valve and normally 

closed valve 

ON 

(two valves and the 

pump power on 

simultaneously) 

Pedal 

The pedal does not go down 

when the left front wheel is 

capable of rotating freely 

Inspection to normally 

open valve 

ON Pedal 

The pedal does not go down 

when the right front wheel is 

incapable of rotating 

Inspection to the normally 

closed valve 

Tightness of normally 

open valve and 

normally closed valve of 

front right wheel 

ON 

(two valves and the 

pump power on 

simultaneously) 

Pedal 

The pedal does not go down 

when the right front wheel is 

capable of rotating freely 

Inspection to normally 

open valve 

ON Pedal 

The pedal does not go down 

when the left rear wheel is 

incapable of rotating 

Inspection to the normally 

closed valve 

Tightness of normally 

open valve and 

normally closed valve of 

rear left wheel 

ON 

(two valves and the 

pump power on 

simultaneously) 

Pedal 

The pedal does not go down 

when the left rear wheel is 

capable of rotating freely 

Inspection to normally 

open valve 

ON Pedal 

The pedal does not go down 

when the rear right wheel is 

incapable of rotating 

Inspection to the normally 

closed valve 

Tightness of rear right 

wheel normally open 

valve and normally 

closed valve 

ON 

(two valves and the 

pump power on 

simultaneously) 

Pedal 

The pedal does not go down 

when the rear right wheel is 

capable of rotating freely 

Inspection to normally 

open valve 

 

 
 

 

 

422 

No.322 ECU code   

When replacing HECU or ECU, code new ECU, otherwise ABS warning lamp will flash and the system can not 
operate normally.   

Code ECU with diagnosis scanner as following procedures: 

 

Connect diagnosis scanner and diagnosis socket 

Enter controller code at address (Addresswort eingeben) 

Input 01 and press F1 at function select (Funktion anwählen) 

Input relevant vehicle code at code input (see ABS elementary diagram MK20, 

No.01901, and MK60, No.0004097) 

Display input number, press → 

Input 01 at function select (Funktion anwählen), press F1 

End 

 
 

 

 

423 

No.323 Fluid filling and air exhaust   

Wet HCU

 

When equipped with wet HCU, implement fluid filling and air exhaust according to the requirements of normal 
brake system after HCU replaced. 

Dry HECU 

When equipped with dry HECU, after replacing HECU, not only implement fluid filling and air exhaust 
according the requirements of normal brake system, but also implement air exhaust to 2

nd

 circuit of HECU. The 

procedures when operating with diagnosis scanner are as follows: 

 

Implement fluid filling and air exhaust, until there is no bubble in transparent 

pipe.

Connect diagnosis scanner and diagnosis socket 

At address (Addresswort ein-geben) basic setting, press F1 

Ehnter 01 at function select (Funktion anwählen), press F1 

Enter 01 at group number input (Anzeigegruppen-nummer eingeben), press F1 

Turn to next page 

 
 

 

 

424 

 

Pedal betätigung und halten… 

Press brake pedal and hold, hydraulic pump operates, pedal rebound 

Pedal  10×betätigung,  Ent-lüfterschraube,zu  <↑> 

Press brake pedal 10 times and tighten the air drain screws on left and right 
brake caliper, press ↑ 

Pedal lösen, VR/ VL, Entlüfter-schraube, auf <↑> 
Loose brake pedal, and air drain screws on left and right brake caliper，
press ↑ 

Repeat step I, II, and III for 7 times. 

Teilentlüftung beendet… 

Screen display, air exhaust finished, press → and return to function select 

menu. 

Enter 02 at function select (Funktion anwählen), press F1 

End 

Continued from previous page