Engine Oil Pressure Switch (S5) Open — Shutdown
The DOOSAN-CODE-5 (Doosan/Ingersoll-Rand SECU portables) diesel fault code means: Engine Oil Pressure Switch (S5) Open — Shutdown. This is a critical severity code.
- DIY difficulty
- moderate
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Common Symptoms
- Machine shuts down and SECU display shows code 5
- Possible genuine loss of engine oil pressure
Probable Causes (Ranked by Likelihood)
- Actual loss of engine oil pressure High
- Faulty S5 oil pressure switch Moderate
- Wiring fault between S5 and SECU (wires W008 / W089) Moderate
Frequently Asked Questions
What does code 5 mean?
The SECU detected an open S5 engine oil pressure switch for one second while running and shut the machine down. That either means real oil-pressure loss or a failed switch/wiring. Check the oil level before anything else, and treat repeated trips as a real lubrication problem until proven otherwise.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
This code set applies to SECU-display machines (7/51, 7/71, XP185, P260). Newer Tier-4-Final Doosan portables such as the P185WDOU-T4F use a DIFFERENT code set (CPR codes) — confirm which controller your machine has before acting on this page.
CHECK THE ENGINE OIL LEVEL FIRST — the factory procedure starts there, because the SECU shuts the machine down if this switch is open for 1 second while running.
Check continuity of wire W008 from S5 pin 2 to SECU controller pin 26.
Check continuity of wire W089 from S5 pin 1 to splice E16.
If oil level and wiring are good, replace the S5 switch (side of the engine block). Do not keep restarting against a possible real oil-pressure loss.
Sources 1
This page is built from documented references. Verify against your own service info before repair work.
- Doosan Portable PowerElectronic Service Manual, Book 23307366 Rev A: Compressor Fault Codes (official dealer service documentation for 7/51, 7/71, XP185, P260)
Commonly Affected Vehicles
- Doosan / Ingersoll-Rand SECU-controller portable compressors: 7/51, 7/71, XP185, P260
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