Power Interruption — Intermittent Control Power
The SULLAIR-POWER-INTERRUPTION (Sullair WS Controller) diesel fault code means: Power Interruption — Intermittent Control Power. This is a moderate severity code.
- DIY difficulty
- moderate
A $30 car code reader can't do diesel. The HD7000 reads full-system codes and does parked DPF regen, idle/speed-limit, and service resets from the cab — on everything from a 6.7 Cummins/Power Stroke/Duramax pickup to Class-8 trucks (Detroit, Paccar, CAT, Volvo, Mack, International).
Full-system 6/9/16-pin diesel scan tool for Cummins, Paccar, CAT, Detroit and more — plug-and-play, no subscription. A cheaper way to read heavy-duty codes a basic OBD2 scanner skips entirely.
Affiliate links — we earn a commission at no extra cost to you.
Common Symptoms
- WS display shows Power Interruption
Probable Causes (Ranked by Likelihood)
- Intermittent control power High
- Loose supply connections Moderate
Frequently Asked Questions
Will the compressor restart itself after an outage?
It can — per the manual, if the restart timer is greater than zero and the controller was in Automatic or Manual mode before the interruption, it resumes that mode after the timer expires with no key press. Treat a powered machine as one that may start on its own.
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.
Check line voltage and supply connections.
Per the manual's power-interruption behavior: a previously faulted machine resumes FAULTED with the reason displayed; a manually stopped machine stays stopped; a machine that was in Automatic/Manual with a restart timer resumes by itself after the timer expires — do not assume a machine that lost power will stay off.
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
Explore More
Was this helpful?
Send this to whoever is fixing the truck — your tech, or the person asking what the fault means.