Barometric Pressure Sensor: Testing and Inspection
Barometric Pressure (BARO) Sensor, Checking
NOTE:
The signal from Barometric Pressure (BARO) sensor -F96- influences:
- Boost pressure limit
- Mixture composition at engine start-up
Required special tools and test equipment
- VAG 1551 or VAG 1552 Scan Tool (ST) with VAG 1551/3 adapter cable
- VAG 1598/22 test box
- Multimeter US 1119 (Fluke 83 or equivalent)
- VW 1594 connector test kit
- Wiring diagrams
Checking
- Connect VAG 1551 or VAG 1552 scan tool and press buttons -0- and -1- to insert "Engine Electronics" address word 01 (with engine running at idle). Refer to "Scan Tool Testing/Scan Tool Connecting and Initial Checks/Connecting VAG 1551/1552 Scan Tool" Testing and Inspection
Indicated on display
Rapid data transfer HELP
Select function XX
- Press buttons -0- and -8- to select "Read Measuring Value Block" function 08, and press -Q- button to confirm input.
Indicated on display
Read Measuring Value Block HELP
Input display group number XXX
- Press buttons -1-, -1- and -3- to input display group number 113, and press -Q- button to confirm input.
Indicated on display (1-4 = display fields)
Read Measuring Value Block 113 ->
1 2 3 4
- Compare displayed value with specified air pressure value (display field 4):
Display Group 113:
- Check air pressure with turbocharger tester VAG 1597/A (actual pressure indication) and compare with displayed value.
If the displayed value is so high or low that it seems implausible for the altitude or the air pressure:
- Check wiring and terminals for excessive resistance.
If displayed value is NOT OK:
- Check readiness code. If Diagnostic Trouble Code (DTC) memory has been erased, or ECM was disconnected, generate new readiness code.
Refer to "Monitors, Trips and/or Drive Cycle/Displaying Readiness Code" Testing and Inspection
Refer to "Monitors, Trips and/or Drive Cycle/Generating Readiness Code" Testing and Inspection
- Press -> button to advance program sequence.
- Press buttons -0- and -6- to select "End Output" function 06, and press -Q- button to confirm input.
Checking wiring
- Disconnect harness connector from Barometric Pressure (BARO) sensor.
- Switch ignition on.
- Connect multimeter US 1119 (Fluke 83 or equivalent) and check voltage between connector terminals 1 and 3 (Ground) as well as 2 and 3 (Ground), using adapter cables from VW 1594 connector test kit.
Specified value for both: 4.5 - 5.5 volts
If voltage is NOT OK:
- Switch ignition off.
- Connect VAG 1598/22 test box to ECM harness connector. Refer to "Scan Tool Testing/Scan Tool Connecting and Initial Checks/Connecting VAG 1598/22 Test Box" Testing and Inspection
- Check wiring for open circuit between ECM/test box and 3-pin harness connector, according to wiring diagram.
- Connector terminal 1 to ECM/test box socket 61
- Connector terminal 2 to ECM/test box socket 62
- Connector terminal 3 to ECM/test box socket 67
- Specified value: max. 1.5 Ohms
- Check wiring for short circuits between terminals of 3-pin connector, and between connector and ECM/test box.
- Connector terminal 2 to ECM/test box socket 61
- Connector terminal 3 to ECM/test box socket 61
- Connector terminal 3 to ECM/test box socket 62
- Specified value: Infinity Ohms
If wiring is OK:
- Replace Barometric Pressure (BARO) sensor.
If an implausible value is still displayed after replacing the barometric pressure sensor:
- Replace Motronic ECM -J220-.
- Carry out adaptation of throttle valve control module to ECM.
- Check readiness code. If Diagnostic Trouble Code (DTC) memory has been erased, or ECM was disconnected, generate new readiness code.
Refer to "Monitors, Trips and/or Drive Cycle/Displaying Readiness Code" Testing and Inspection
Refer to "Monitors, Trips and/or Drive Cycle/Generating Readiness Code" Testing and Inspection