Audi A4 Workshop Service and Auto Repair Manuals

Electrical testing of solenoid valve for boost pressure limitation -N75

• ‒ Pull connector off valve => Overview of fitting locations, Page 23-6.
• ‒ Measure resistance with hand-held multimeter V.A.G 1526 between contacts of solenoid valve.

→ Engine code AFF, 1Z

• Desired value: 25 ... 45 ω

→ Engine code AFN

• Desired value: 14 ... 20 ω

• ‒ If the desired value is not attained, replace solenoid valve for boost pressure limitation -N75.

Testing voltage supply of solenoid valve for boost pressure limitation -N75.

• ‒ Pull connector off valve => Overview of fitting locations, Page 23-6.
• ‒ → Use auxiliary leads from V.A.G 1594 to connect hand-held multimeter V.A.G 1526 to contact 2 of connector and to earth.
• ‒ Activate 20 V measuring range.
• ‒ Switch on ignition.

• Desired value: approx. battery voltage

• ‒ If desired value is not attained, test cable connections to valve -N75.

Testing cable connection to solenoid valve for boost pressure limitation -N75.

• ‒ Pull connector off valve => Overview of fitting locations, Page 23-6.
• ‒ Connect test box

Check the following cable connections for short circuit to positive/negative and breaks.

• ‒ If applicable, eliminate cable break/short circuit.