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Electrical check on ABS/EDL/ASR/ESP ITT Mark 20 IE > < Reading measured value block

A2

Running gear self-diagnosis for ESP, steering
Performing self-diagnosis
Final control diagnosis

The final control diagnosis function can be used to check the pump motor as well as correct functioning of the hydraulic circuits (assignment of brake pressure pipes to wheel brakes and function of valves). It is also possible to detect interchanged connections and leaks.

Notes:

  • ◆ Vehicle must be raised so that wheels are free to turn (second mechanic required to turn wheels).
  • ◆ Exit from test sequence can be effected at any time by pressing C key.
  • ◆ Pressing the brake pedal several times dissipates the vacuum in the brake servo. More pressure thus has to be applied to the brake pedal to attain the same fluid pressure in the brake system as that achieved with vacuum.
  • ◆ When the vacuum in the brake servo is exhausted, the wheels may not lock => start engine to build up vacuum in brake servo.

Abbreviations: Examples
 
→ e.g. Indicated on display:
Final control diagnosis    - ⇒
Ifl: UBAT    Ofl: 0V    fl wheel locked

fl = front left

fr = front right

rl = rear left

rr = rear right

I = Inlet valve

O = Outlet valve

UBAT = Battery voltage; voltage applied to valve

0V = 0 volts; no voltage applied to valve

locked/free = Wheel status; must be checked by second mechanic
 
→ e.g. Indicated on display (on vehicles with EDL):
Final control diagnosis    - ⇒
EDL valves/Hydr-P: UBAT    fl/fr wheel locked

Hydr-P = Hydraulic pump

  • ‒ Switch on ignition.
  • ‒ Release handbrake.
  • ‒ Connect up fault reader V.A.G 1551 and select brake electronics control unit with address word 03.
 
→ Indicated on display:
Rapid data transfer    HELP
Select function XX
  • ‒ Press keys 0 and 3.
 
→ Indicated on display:
Rapid data transfer    Q
03 - Final control diagnosis
  • ‒ Confirm entry with Q key.

Note:

In the course of the next steps, the ABS warning lamp flashes 4 times per second.
 
→ Indicated on display:
Final control diagnosis    - ⇒
ABS hydraulic pump - V64

ABS hydraulic pump -V64 must start up.

  • ‒ Press ⇒ key within the next 10 s.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Press brake

Brake pedal must not sag.

  • ‒ Press ⇒ key.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Ifl: 0V    Ofl: 0V    fl wheel locked
  • ‒ Press ⇒ key.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Ifl: UBAT    Ofl: 0V    fl wheel locked
  • ‒ Press ⇒ key.

ABS hydraulic pump -V64 must start up.

Brake pedal must not sag.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Ifl: UBAT    Ofl: UBAT    fl wheel free
  • ‒ Press ⇒ key within the next 10 s.

ABS hydraulic pump -V64 stops running.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Ifl: UBAT    Ofl: 0V    fl wheel free
  • ‒ Press ⇒ key.

Brake pedal must sag noticeably.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Ifl: 0V    Ofl: 0V    fl wheel locked
  • ‒ Press ⇒ key.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Release brake
  • ‒ Press ⇒ key.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Press brake
  • ‒ Press ⇒ key.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Ifr: 0V    Ofr: 0V    fr wheel locked
  • ‒ Press ⇒ key.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Ifr: UBAT    Ofr: 0V    fr wheel locked
  • ‒ Press ⇒ key.

ABS hydraulic pump -V64 must start up.

Brake pedal must not sag.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Ifr: UBAT    Ofr: UBAT    fr wheel free
  • ‒ Press ⇒ key within the next 10 s.

ABS hydraulic pump -V64 stops running.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Ifr: UBAT    Ofr: 0V    fr wheel free
  • ‒ Press ⇒ key.

Brake pedal must sag noticeably.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Ifr: 0V    Ofr: 0V    fr wheel locked
  • ‒ Press ⇒ key.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Release brake
  • ‒ Press ⇒ key.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Press brake
  • ‒ Press ⇒ key.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Irl: 0V    Orl: 0V    rl wheel locked
  • ‒ Press ⇒ key.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Irl: UBAT    Orl: 0V    rl wheel locked
  • ‒ Press ⇒ key.

ABS hydraulic pump -V64 must start up.

Brake pedal must not sag.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Irl: UBAT    Orl: UBAT    rl wheel free
  • ‒ Press ⇒ key within the next 10 s.

ABS hydraulic pump -V64 stops running.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Irl: UBAT    Orl: 0V    rl wheel free
  • ‒ Press ⇒ key.

Brake pedal must sag noticeably.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Irl: 0V    Orl: 0V    rl wheel locked
  • ‒ Press ⇒ key.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Release brake
  • ‒ Press ⇒ key.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Press brake
  • ‒ Press ⇒ key.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Irr: 0V    Orr: 0V    rr wheel locked
  • ‒ Press ⇒ key.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Irr: UBAT    Orr: 0V    rr wheel locked
  • ‒ Press ⇒ key.

ABS hydraulic pump -V64 must start up.

Brake pedal must not sag.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Irr: UBAT    Orr: UBAT    rr wheel free
  • ‒ Press ⇒ key within the next 10 s.

ABS hydraulic pump -V64 stops running.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Irr: UBAT    Orr: 0V    rr wheel free
  • ‒ Press ⇒ key.

Brake pedal must sag noticeably.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Irr: 0V    Orr: 0V    rr wheel locked
  • ‒ Press ⇒ key.
 
→ Indicated on display:
Final control diagnosis    - ⇒
Release brake
  • ‒ Press ⇒ key.
 
→ Indicated on display:
Final control diagnosis    - ⇒
EDL valves/Hydr-P: UBAT Wheels locked

ABS hydraulic pump -V64 must start up.

  • ‒ Press ⇒ key.

Note:

ABS warning lamp and brake system warning lamp go out.
 
→ Indicated on display:
Function unknown or cannot     - ⇒
be implemented at present

Note:

Final control diagnosis is over.

  • ‒ Press ⇒ key.
 
→ Indicated on display:
Rapid data transfer    HELP
Select function XX

Notes:

  • ◆ There is a fault in the system if the ABS warning lamp does not go out.
  • ◆ Keep exactly to test sequence:
    Interrogate fault memory first and then erase it
  • ‒ End output .

Electrical check on ABS/EDL/ASR/ESP ITT Mark 20 IE > < Reading measured value block