Manifold Pressure/Vacuum Sensor: Testing and Inspection

Both Manifold Absolute Pressure Sensor and Barometric Sensors are located inside the Diesel TDI Engine Control Module.

Special Tools, Testers And Auxiliary Items:
- VAG 1551/1552 Scan Tool with VAG 1551/3 adaptor cable
- VAG 1397/A turbocharger test unit

Test Sequence:
- Connect VAG 1551/1552 Scan Tool
- Switch ON ignition (but do not start engine)
- Press 0 and 1 buttons to select address word 01 "engine electronics"
Display will appear as shown:

Rapid data transfer HELP
select function XX

- Press 0 and 8 buttons to select Function 08 "Read measuring value block"
- Press Q button to enter 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 number 10
- Press Q button to enter input
Display will appear as shown:

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

- Compare display zone 2 (BARO sensor F96) with display zone 3 (Manifold Absolute Pressure sensor G71)
Specification: pressures must be the same ± 30 mbar

If specification not obtained:
- Compare pressure display with VAG 1397/A
Tolerance ± 30 mbar

If value in display zone 3 deviates:
- Disconnect pressure hose from ECM

If value in display zone 3 still deviates:
- Press -> button
- Press 0 and 6 buttons to select Function 06 "end data transfer"
- Press Q button to enter input
- Switch OFF ignition
- Replace ECM J248
- Display the readiness code

If DTC memory was erased:
- Create readiness code again