Vacuum Pump: Testing and Inspection
Electric vacuum pump, checking
- Functions of vacuum pump can be checked via On Board Diagnostic (OBD).
Only check electric vacuum pump with vehicle stationary.
On Board Diagnostic (OBD), technical data
Equipment:
- Data transmission between control module and VAS5051 scan tool or VAG1551 scan tool is done in mode "Rapid data transfer".
- DTC memory is a permanent memory and will store DTC's even if power supply is interrupted.
VAS5051 scan tool or VAG1551 scan tool, connecting and selecting mode
Notes: Test conditions:
- battery voltage 11 V minimum
- Ground (GND) cable connection at engine and transmission O.K.
- Engine off
- Automatic transmission in position "P" or "N"
Operation sequence:
- Connect VAS5051 scan tool with diagnostic cable VAS 5051/1 with ignition switched off or connect VAG1551 scan tool with diagnostic cable VAG1551/3B.
Note: During the following description, the On Board Diagnostic (OBD) is only initiated on scan tool VAG1551. If using VAS5051, observe operating instructions.
Indicated on display: 1) appears alternately
Note: If nothing appears on the display:
- See Scan tool operating instructions
- Switch off ignition
- Turn on printer by pressing the PRINT button. The button should be illuminated.
- Press button for "Rapid data transfer".
Indicated on display
Note: Address word 00 automatically checks DTC memory, i.e. data of DTC memory will come up automatically.
- Press buttons -0- and -1- to input address word "01" for "engine electronics". Press -Q- button to confirm input.
Indicated on display
Control module identification is indicated on display of scan tool VAG1551, e.g.:
Note: By pressing PRINT button of the scan tool V.A.G. 1551 control module identification is printed out.
Identification of control unit (example)
- 3B0907552 A Part #;See Part Supplier.
- 2.7 L displacement
- V6/5V type of engine
- "G" or no display vehicle with or without cruise control
- 0002 update of control unit (software version)
- Code 05002 Control module coding
- WSC 12345 Dealership number which last coded the control module using VAG1551 scan tool
Basic Setting
- Press (arrow) button until following display appears:
Indicated on display
- Press buttons 0 and 4 to select basic setting (function 04). Press -Q- button to confirm input.
Indicated on display
- Press buttons 0, 0 and 8 to select "Performing Short trip UP 28". Press -Q- button to confirm input.
Indicated on display
- Push brake pedal several times (brake booster) until test is activated.
Indicated on display
- Brake pedal must not be used during test activation.
Pump evacuates brake booster. On Board Diagnostic (OBD) for brake booster system is carried out simultaneously in the control module. Test is passed if pressure in brake booster reaches the cut-off pressure in allowed time (20 sec.).
Indicated on display
- Disconnect diagnostic cable from Data Link Connector (DLC).
Or:
Indicated on display
If system is identified as not O.K., DTC memory must be checked and the malfunction must be repaired (ignition off!).
- Test must be repeated afterward.
Output Diagnostic Test Mode (function 03)
- Connect scan tool with diagnostic cable and select function "engine electronics".
- - Press (arrow) button.
Indicated on display
- Press buttons O and 3 for output diagnostic test mode and press Q button to confirm input.
- Press (arrow) button until the following text appears:
Indicated on display
- Press Q button to confirm input.
The electric vacuum pump must run for about 10 sec.!
- Disconnect diagnostic cable from Data Link Connector (DLC)