With Manufacturer's Scan Tool

Manifold Absolute Pressure (MAP) Sensor And Barometric Pressure (Baro) Sensor, Checking

The altitude sensor is located in the Diesel direct injection system control module. The manifold absolute pressure sensor is a separate component and is located in the pipe between the charge air cooler and intake manifold.

NOTE: Only gold-plated contacts may be used to repair the terminals in the manifold absolute pressure sensor with intake manifold temperature sensor.

Special tools and equipment
- V.A.G 1551/VAG 1552 with adapter cable VAG 1551/3
- Test box VAG 1598/22 (through my 1999)
- Test box VAG 1598/31 (from my 2000)
- Digital multimeter US1119 (Fluke 83 or equivalent)
- Adapter set VAG 1594
- Wiring diagram

Test sequence
- Connect V.A.G 1551/1552 (Connecting scan tool and selecting engine electronics control module.)
- Run engine at idle speed and press buttons -0- and -1- to select "Engine electronics" address word 01.

Indicated on display

Rapid data transfer HELP
Select function XX

- Press buttons -0- and -8- to select "Read measured value block" function 08 and confirm entry with -Q- button.

Indicated on display

Read measured value block HELP
Input display group number XXX

- Press buttons -0-, -1- and -0- to select "Display group number 10" and confirm entry with -Q- button.
- Compare display in display field 2 (BARO Sensor -F96-) with display field 3 (MAP Sensor -G71-).

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

- Specification: The pressures must be the same (tolerance ±30 mbar)

If the specification is obtained:
- Press -> button.
- Press buttons -0- and -6- to select "End output" function 06 and confirm entry with the -Q- button.
- Switch ignition off.

If value in display field 2 deviates:
- Replace engine control module. Testing and Inspection

Value in display field 3 deviates:
- Press the -> button.
- Press buttons -0- and -6- to select "End output" function 06 and confirm entry with -Q- button.
- Switch ignition off.
- Remove wiper arms and plenum cover:






- Connect test box VAG 1598/22 (through my 1999) or VAG 1598/31 (from my 2000) to control module wiring harness.






- Disconnect 4-pin connector from MAP sensor -G71- with Intake Air Temperature (IAT) Sensor -G72- (arrow).










- Check wiring between test box and connector for open circuit according to wiring diagram.
- Wire resistance: max. 1.5 ohms

- Additionally check wires for short to one another, to vehicle ground and to battery positive (B+).

- Specification: Infinity ohms
- If no wiring malfunction is detected, replace engine control module.