With Manufacturer's Scan Tool

Charge Air Pressure Sensor -G31-, Checking







Special and equipment
- VAG 1526 A Hand multimeter
- VAG 1594 A Adapter set
- VAG 1598/31 Test box
- Wiring diagram

Check conditions
- Board Diagnostic (OBD) has detected a malfunction with the charge air pressure sensor.
- Ignition switched off.

Checking voltage supply and wiring to control module







- Disconnect 4-pin connector -2- of Charge air pressure sensor -G31- -1-.







- Connect multimeter to measure voltage to terminals 1 (Ground) and 3 (positive) of connector for charge air pressure sensor using adapter cables from VAG 1594.
- Switch ignition on.
Specification: min. 4.5 V

- Switch ignition off.

If no voltage is present:







- Connect test box VAG 1598/31 to control module wiring harness. Engine control module remains disconnected.







- Check wiring between test box and connector for open circuit according to wiring diagram.

Contact 1 + socket 108
Contact 3 + socket 98
Contact 4 + socket 101

Wire resistance: Max. 1.5 Ohms

- Additionally check wires for short to one another.

If no wiring malfunction is detected and voltage was present between terminals 1+3:

If no wiring malfunction is detected and voltage was not present between terminals 1+3:
- Replace engine control module:

Checking function
- Connect test box VAG 1598/31 to engine control module wiring harness and to engine control module.
- Reconnect connector to Charge air pressure sensor -G31-.
- Connect multimeter to measure voltage to sockets 101 (positive) and 108 (Ground) using adapter cables from VAG 1594.
- Start engine and measure basic voltage.
Specification: 1.80 to 2.00 V

- Raise engine revs by pressing accelerator to
Specification: 2.00 to 3.00 V

If the specifications are not attained.
- Replace Charge air pressure sensor -G31-.
- Check DTC memory.
- Read readiness code.
- Generate readiness code again if DTC memory has been erased or engine control module separated from permanent positive.