Internal Com Error — Module Network Fault
The SULLAIR-INTERNAL-COM-ERROR (Sullair WS Controller) diesel fault code means: Internal Com Error — Module Network Fault. This is a serious severity code.
- DIY difficulty
- moderate
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Common Symptoms
- WS display shows Internal Com Error
Probable Causes (Ranked by Likelihood)
- Communication failed between the Display Module, I/O Module and other modules High
- Wiring fault between modules Moderate
Frequently Asked Questions
Is my controller dead?
Not necessarily. The message means the display and I/O modules stopped talking, and the factory's first remedy is checking the inter-module wiring. Module replacement is the last resort, not the first.
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 the wiring between the controller's modules — the factory remedy is wiring first, not module replacement.
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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