Low Fluid Pressure
The SULLAIR-LOW-FLUID-PRESSURE (Sullair WS Controller) diesel fault code means: Low Fluid Pressure. This is a serious severity code.
- DIY difficulty
- moderate
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Common Symptoms
- WS display shows Low Fluid Pressure
Probable Causes (Ranked by Likelihood)
- Fluid filter clogged High
- Sump fluid level low High
- Low ambient temperature Moderate
- Fluid pump failure (remote-cooler installations) Moderate
Frequently Asked Questions
Why does cold weather trigger this?
Cold fluid is thick fluid: below about 40°F (4°C) it resists flowing, which reads as low fluid pressure. The factory remedy is a sump heater rather than parts replacement.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
The WS Controller is fitted to Sullair STATIONARY electric shop compressors. Portable towable Sullair units (185-class and similar) use different engine-driven controls and a different fault system — this page does not apply to them.
Replace the fluid filter and replenish fluid to the proper level.
In ambients below 40°F (4°C) a sump heater may be required.
On installations with remote coolers, a fluid pump may be required — consult Sullair factory service.
Per the factory manual: after resolving a fault condition, press the STOP pad to clear the FAULTED state. If the problem persists after the recommended checks, consult your Sullair distributor or factory service.
Sources 1
This page is built from documented references. Verify against your own service info before repair work.
- Sullair WS Controller User Interface Manual, P/N 02250165-411 (Table 5-1 Troubleshooting Guide)distributor-hosted copy of the official Sullair manualdistributor-hosted copy of an official Sullair factory manual
Commonly Affected Vehicles
- Sullair STATIONARY electric rotary-screw compressors with the WS Controller (including VSD packages)
Related Codes
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