Manifold Pressure/Vacuum Sensor: Testing and Inspection

Both Manifold Absolute Pressure Sensor and Barometric Sensors are located inside the Diesel Direct Fuel Injection (DFI) Engine Control Module.

Special tools, testers and auxiliary items:

-VAG1551 or VAG1552 Scan Tool (ST)
-VAG1551/3 adaptor cable
-VAG1397/A turbocharger tester

Test Sequence:

Connect VAG1551 or VAG1552 scan tool
Switch ignition ON (but do not start engine)
Press -0- and -1- buttons to insert "Engine Electronics" address word 01
Display will appear as shown:

Rapid data transfer HELP
select function XX

Press -0- and -8- buttons to select "Read Measuring Value Block" function 08, and press -Q- button to confirm input
Display will appear as shown:

Read measuring value block HELP
Input display group number XXX

Press -0-, -1- and -0- buttons to select display group No. 10 (010)
Press -Q- button to confirm input
Display will appear as shown:

Read measuring value block 10 ->
0 mg/H 1027 mbar 1013 mbar 0.0%

Compare values in display field 2 (BARO sensor -F96-) with display field 3 (MAP sensor -G71-)

Specification: pressures equal (±30 mbar)

If pressures are not equal (as specified):
- Compare scan tool values with pressure measured using VAG1397/A turbocharger tester
Specification: pressures equal (±30 mbar)

If value in display field 3 deviates:
- Disconnect pressure hose from Diesel DFI ECM

If value in display field 3 still deviates:
-Press -> button
-Press -0- and -6- buttons to select "End Output" function 06, and press -Q- button to confirm input
-Switch OFF ignition
-Replace Diesel DFI ECM -J248-
-Display the readiness code

If DTC memory was erased:
-Create readiness code again