SULLAIR-LOW-LINE-PRESSURE moderate Sullair WS Controller

Low Line Pressure — Demand Exceeds Capacity

The SULLAIR-LOW-LINE-PRESSURE (Sullair WS Controller) diesel fault code means: Low Line Pressure — Demand Exceeds Capacity. This is a moderate severity code.

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Keep driving?
Yes, but fix soon
DIY difficulty
moderate
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Common Symptoms

  • WS display shows Low Line Pressure
  • Air tools or process starved downstream

Probable Causes (Ranked by Likelihood)

  • Demand exceeds compressor capacity High
  • Leaks or open lines in the air supply High

Step-by-Step Diagnostic Procedure

  1. 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.

  2. Reduce demand or increase capacity — this is a sizing/usage condition, not a machine fault.

  3. Check the supply lines for leaks or open drops and repair as necessary.

  4. 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.

Frequently Asked Questions

Is the compressor broken?

Usually not — the factory's causes are demand exceeding capacity and supply-line leaks. The machine is telling you it cannot keep up, which is a system problem before it is a compressor problem.

Sources

This page is built from documented references. Verify against your own service info before repair work.

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