Audi Workshop Service and Repair Manuals

Special tools and workshop equipment required

• ◆ V.A.G 1526 A
• ◆ V.A.G 1594 A
• ◆ V.A.G 1598/31
• ◆ VAS 5051 with VAS 5051/1

• or

• ◆ V.A.G 1551 with V.A.G 1551/3 A

The function of the power steering pressure switch is to stabilise the idling speed when the steering wheel is on full lock (left or right).

Test sequence

• ‒ Connect vehicle diagnostic, testing and information system VAS 5051 (or fault reader V.A.G 1551) and select engine electronics control unit by entering address word "01" ( .)
  When doing this the engine must be idling.

• ‒ Enter "08" to select the function "Read measured value block" and confirm entry with Q key.

• ‒ Enter "056" for Display Group 056 and confirm entry with Q key.

• ‒ Check display value for power steering pressure switch (display zone 4).

If the display values do not appear as described:

Testing switch

• ‒ Unplug connector from power steering pressure switch -F88 on power steering pump.

• ‒ → Connect multimeter to switch (resistance measurement range).
• ‒ Start the engine.
• ‒ Specification: ∞ ω (no continuity)
• ‒ Turn steering wheel to full lock (left and right).
• ‒ Specification: approx. 0 ω

If the display does not change:

• ‒ Renew power steering pressure switch -F88.

If the display changes:

• ‒ Test the wiring => Page 24-169.

Testing wiring

• ‒ Connect test box V.A.G 1598/31 to wiring harness for engine control unit. Do not connect to the engine control unit itself.
  => Page 24-16.

• ‒ → Test for open circuit and short to positive or earth in the following wiring connections:

• ‒ Rectify short circuit or open circuit if necessary.