What does P1189 mean on a Chevy?

P1189. Engine Oil Pressure (EOP) Switch Circuit. Applies to Silverado, Sierra, Tahoe, Suburban, Avalanche.

What causes P1189 on a Chevy?

Failed oil pressure switch stuck open or closed Oil-soaked EOP connector from a leaking switch Clogged oil pressure switch screen under the sensor Chafed EOP signal wire near the back of the engine Low oil level or wrong-viscosity oil skewing pressure

How do I fix P1189 on a Chevy?

Check oil level and condition before any electrical testing Remove the EOP switch and inspect the filter screen for sludge Test switch continuity against actual pressure with a mechanical gauge Inspect the EOP harness for oil wicking and chafing Replace the switch and screen only after verifying true oil pressure, then clear and road test

Code

P1189

Engine Oil Pressure (EOP) Switch Circuit

Category: Powertrain - Computer and Auxiliary Controls
Severity: Check Engine Light
Applies to: Silverado, Sierra, Tahoe, Suburban, Avalanche
Related: No single generic twin. See OBD Codes List

What it means

P1189. Engine Oil Pressure (EOP) Switch Circuit. This Chevy-enhanced code applies to Silverado, Sierra, Tahoe, Suburban, Avalanche.

Findings, check these first

Failed oil pressure switch stuck open or closed
Oil-soaked EOP connector from a leaking switch
Clogged oil pressure switch screen under the sensor
Chafed EOP signal wire near the back of the engine
Low oil level or wrong-viscosity oil skewing pressure

Standard procedure

Check oil level and condition before any electrical testing
Remove the EOP switch and inspect the filter screen for sludge
Test switch continuity against actual pressure with a mechanical gauge
Inspect the EOP harness for oil wicking and chafing
Replace the switch and screen only after verifying true oil pressure, then clear and road test

Look up another code

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Sources and review

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Last updated 2026-09-13.

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