Output Diagnostic Test Mode (DTM)
Output Diagnostic Test Mode (DTM)
Note:
- All functions which could previously be performed with V.A.G. 1551 can also be performed with the tester VAS 5051.
- The pump motor and the correct functioning of the hydraulic circuits (allocation of brake lines to wheel cylinders and function of valves) can be checked via the output DTM for interchange or leaks.
- The vehicle must be raised until all wheels are free to turn. (2nd mechanic required to rotate wheels)
- The -C- key can be used to exit the test sequence at any time.
- After depressing the brake pedal several times the vacuum in the brake booster will be exhausted. Therefore more pressure must be applied to the brake pedal in order to attain the same fluid pressure in brake system, as that attained with vacuum.
- When vacuum in brake booster is exhausted wheels may not lock; start engine and build-up vacuum in brake booster.
Example: Indicated on V.A.G 1551 display during output Diagnostic Test Mode (DTM):
(e.g. front left wheel, FL)
IFL = Inlet valve Front Left
VBAT = Voltage Battery; Voltage at valve
0FL = Outlet valve Front Left
0V = 0 Volt; No voltage at valve
Locked/free = Wheel condition; must be checked by 2nd mechanic if required
Hydr-P = Hydraulic pump
- Connect V.A.G. 1551 Scan Tool.
- Switch ignition on.
- Press key -1- for "Rapid data transfer" operating mode.
- Select brake electronics (address word 03)
Indicated on display
- Confirm entry with key Q.
Note: During the next work steps the ABS warning light -K47- flashes.
- Read off control module version in V.A.G 1551 display.
- Press (arrow) key.
Indicated on display
- Press keys 0 and 3
Indicated on display
- Confirm entry with key Q.
- ABS hydraulic pump -V64- must run.
Indicated on display
- Press (arrow) key.
Indicated on display
- Operate brake pedal.
- Press (arrow) key.
Indicated on display
- Indicate to 2nd mechanic which wheel requires turning by hand.
Note: If the wheel does not lock, there is a possibility that there is a malfunction in the mechanical/hydraulic part of the brake system.
- Press (arrow) key.
Indicated on display
- Press (arrow) key.
- ABS hydraulic pump -V64- must run.
- Brake pedal must not give.
If the brake pedal gives, there is a malfunction in the hydraulic unit. In this case the hydraulic unit must be replaced.
Indicated on display
- Indicate to 2nd mechanic which wheel requires turning by hand.
Note: If the wheel locks there is a possibility that the brake lines to the wheel calipers/cylinders have been interchanged.
- Press (arrow) key.
- ABS hydraulic pump -V64- no longer runs.
Indicated on display
- Press (arrow) key.
- Brake pedal must give perceptibly
If the brake pedal does not give, there is a malfunction in the hydraulic unit. In this case the hydraulic unit must be replaced.
Indicated on display
- Indicate to 2nd mechanic which wheel requires turning by hand.
Note: If the wheel does not lock, there is a possibility that there is a malfunction in the mechanical/hydraulic part of the brake system.
- Press (arrow) key.
Indicated on display
- Remove foot from brake pedal.
- Press (arrow) key.
Indicated on display
- Operate brake pedal.
- Press (arrow) key.
Indicated on display
- Indicate to 2nd mechanic which wheel requires turning by hand.
Note: If the wheel does not lock, there is a possibility that there is a malfunction in the mechanical/hydraulic part of the brake system.
- Press (arrow) key.
Indicated on display
- Press (arrow) key.
- ABS hydraulic pump -V64- must run.
- Brake pedal must not give
If the brake pedal gives, there is a malfunction in the hydraulic unit. In this case the hydraulic unit must be replaced.
Indicated on display
- Indicate to 2nd mechanic which wheel requires turning by hand.
Note: If the wheel locks there is a possibility that the brake lines to the wheel calipers/cylinders have been interchanged.
- Press (arrow) key.
- ABS hydraulic pump -V64- no longer runs.
Indicated on display
- Press (arrow) key.
- Brake pedal must give perceptibly
If the brake pedal does not give, there is a malfunction in the hydraulic unit. In this case the hydraulic unit must be replaced.
Indicated on display
- Indicate to 2nd mechanic which wheel requires turning by hand.
Note: If the wheel does not lock, there is a possibility that there is a malfunction in the mechanical/hydraulic part of the brake system.
- Press (arrow) key.
Indicated on display
- Remove foot from brake pedal.
- Press (arrow) key.
Indicated on display
- Operate brake pedal.
- Press (arrow) key.
Indicated on display
- Indicate to 2nd mechanic which wheel requires turning by hand.
Note: If the wheel does not lock, there is a possibility that there is a malfunction in the mechanical/hydraulic part of the brake system.
- Press (arrow) key.
Indicated on display
- Press (arrow) key.
- ABS hydraulic pump -V64- must run.
- Brake pedal must not give
If the brake pedal gives, there is a malfunction in the hydraulic unit. In this case the hydraulic unit must be replaced.
Indicated on display
- Indicate to 2nd mechanic which wheel requires turning by hand.
Note: If the wheel locks there is a possibility that the brake lines to the wheel calipers/cylinders have been interchanged.
- Press (arrow) key.
- ABS hydraulic pump -V64 no longer runs.
Indicated on display
- Press (arrow) key.
- Brake pedal must give perceptibly
If the brake pedal does not give, there is a malfunction in the hydraulic unit. In this case the hydraulic unit must be replaced.
Indicated on display
- Indicate to 2nd mechanic which wheel requires turning by hand.
Note: If the wheel does not lock, there is a possibility that there is a malfunction in the mechanical/hydraulic part of the brake system.
- Press (arrow) key.
Indicated on display
- Remove foot from brake pedal.
- Press (arrow) key.
Indicated on display
- Operate brake pedal.
- Press (arrow) key.
Indicated on display
- Indicate to 2nd mechanic which wheel requires turning by hand.
Note: If the wheel does not lock, there is a possibility that there is a malfunction in the mechanical/hydraulic part of the brake system.
- Press (arrow) key.
Indicated on display
- Press (arrow) key.
- ABS hydraulic pump -V64- must run.
- Brake pedal must not give
If the brake pedal gives, there is a malfunction in the hydraulic unit. In this case the hydraulic unit must be replaced.
Indicated on display
- Indicate to 2nd mechanic which wheel requires turning by hand.
Note: If the wheel locks there is a possibility that the brake lines to the wheel calipers/cylinders have been interchanged.
- Press (arrow) key.
- ABS hydraulic pump -V64- no longer runs.
Indicated on display
- Press (arrow) key
- Brake pedal must give perceptibly
If the brake pedal does not give, there is a malfunction in the hydraulic unit. In this case the hydraulic unit must be replaced.
Indicated on display
- Indicate to 2nd mechanic which wheel requires turning by hand.
Note: If the wheel does not lock, there is a possibility that there is a malfunction in the mechanical/hydraulic part of the brake system.
- Press (arrow) key.
Indicated on display
- Remove foot from brake pedal.
- Press (arrow) key.
Indicated on display (vehicles with EDL)
Note: A 2nd mechanic is required to rotate the respective wheel by hand.
If the wheels do not lock, there is a malfunction in the hydraulic part of the ABS system. In this case the hydraulic unit must be replaced.
- Press (arrow) key.
- The ABS warning light -K47- goes out.
Indicated on display
The Output Diagnostic Test Mode (DTM) is completed
- Press (arrow) key.
Indicated on display
Note:
- There is a malfunction in the system if the ABS warning light -K47 does not go out.
- Adhere exactly to test sequence: First check Diagnostic Trouble Code (DTC) memory, then erase.
- End output (Function 06).