With Manufacturer's Scan Tool

Charge Air Pressure Sensor -G31-, checking

Special tools and equipment




- VAG 1526 A Hand multimeter
- VAG 1 594A Adapter set
- VAG 1598/31 Test box
- Wiring diagram

Test conditions

- On Board Diagnostic (OBD) has detected a malfunction with the Charge Air Pressure Sensor. Check and erase DTC memory, if necessary: Reading Diagnostic Trouble Codes

- Switch ignition off.

Checking voltage supply and wiring to control module






- Disconnect 4-pin connector 2 from Charge Air Pressure Sensor -G31-.






- Connect multimeter to measure voltage using aux. cables from VAG1594 to contacts 1 (Ground) and 3 (positive) of connector for Charge Air Pressure Sensor.
- Switch ignition on.
Specification: min. 4.5 V
- Switch ignition off.

If no voltage is present:
- Remove inner plenum chamber cover, left side.






- Connect test box VAG 1598/31 to control module wiring harness. Engine Control Module is not connected by this action.






- Check wiring between test box and connector for open circuit according to wiring diagram.
Terminal 1 + socket 108
Terminal 3 + socket 98
Terminal 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:
- Check function.
If no wiring malfunction is detected and no voltage was present between terminals 1 + 3:
- Replace engine control module.

Checking function

- Remove inner plenum chamber cover, left side.
- Connect VAG 1598/31 test box to wiring harness for control module and to control module.
- Re-connect connector at 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

- Bring engine to specified RPM by quickly depressing accelerator pedal.
Specification: 2.00 to 3.00 V

If the specifications are not obtained:
- Replace Charge Air Pressure Sensor -G31-.
- Check DTC memory.
- Read readiness code.

If the DTC memory has been erased or the engine control module separated from the permanent positive, the readiness code must be generated again.