Power Steering Pressure Switch: Testing and Inspection

Signal From Power Steering Pressure Switch, Checking

Special tools and equipment
- Scan tool VAG 1551 or vehicle system tester VAG 1552 with cable VAG 1551/3
- Test box VAG 1598/31
- Hand multimeter VAG 1526 or multimeter VAG 1715
- Adapter set VAG 1594
- Wiring diagram

Test sequence
- Connect scan tool VAG 1551 (VAG 1552). Start engine and select "Address word" 01 of engine control module. When doing this the engine must be running at idling speed.

(Connecting scan tool and selecting engine control module). Refer to "VAG 1551 Scan Tool" [1][2][3][4][5]Connecting VAG 1551 Scan Tool

Indicated on display:


Rapid data transfer HELP
Select function XX


- Press keys 0 and 8 for function "Read measured value block" and confirm entry with Q key.

Indicated on display:


Read measured value block HELP
Input display group number XXX


- Press keys 0, 5 and 6 for "Display group number 56" and confirm entry with Q key.

Indicated on display:


Read measured value block 56 ->
1 2 3 4


- Observe values for power steering pressure switch displayed in display zone 4.
Specification: 0 x x x x
- Turn steering wheel to full lock and observe value displayed in display zone 4 (1st digit from left)
Specification: 1 x x x x
- Press -> key.
- Press keys 0 and 6 for "End output" function and confirm input with the Q key.
- Switch off ignition.

If the specification is not obtained:
- Connect multimeter VAG 1526 to pressure switch contacts.
- Start engine and run at idling speed. Check pressure switch for continuity.
Specification: Infinity ohms
- Turn steering wheel to full lock.
- The pressure switch must switch to continuity.

If the specifications are not attained:
- Replace pressure switch for power assisted steering:

If the specifications are attained:
- Check wiring.

Checking wiring connections







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







- Check wiring between test box and 2-pin connector for open circuit using wiring diagram.
Contact 1 + socket 49
Contact 2 + socket 50
Wire resistance: Max. 1.5 ohms
- Additionally check wires for short to one another.
- Additionally check wiring for short to battery positive or Ground.

If no wiring fault is detected:
- Replace engine electronics control module.