P164DReduced-oil-pressure switch malfunction

• Volkswagen group code · Engine
• Turns on the check-engine light

How the car detects it

VW engines check oil pressure with two switches: one for the low pressure stage and one for the high stage. This code concerns the reduced-pressure switch (brown housing on many engines). Volkswagen lists it with the oil pressure light on EA888 Gen 3 1.8T/2.0T engines. Check the oil level and have the real oil pressure measured before blaming the switch; stop the engine if the red oil-pressure warning stays on.

What you may notice

• Oil pressure warning
• Check-engine light

Likely causes

• PossibleFaulty switch or oil in its connector
• PossibleGenuinely low oil pressure (low oil level, oil pump, filter housing)
• RareWiring

Sources

• static.nhtsa.gov › SB-10072894-0699.pdf · official document
• static.nhtsa.gov › MC-10127873-9999.pdf · official document
• static.nhtsa.gov › MC-10121008-9999.pdf · official document
• static.nhtsa.gov › MC-10118390-9999.pdf · official document

Backed by an official manufacturer document.

From Obdaryn's Volkswagen group pack, exactly as the app shows it, with the public sources above. Guidance only; confirm with a workshop.