Pumper oil pressure sensor circuit (Alarm 3420)
The ATLAS-COPCO-3420 (Atlas Copco Xc-series controller (Xc1004 / Xc2003 / Xc4004)) diesel fault code means: Pumper oil pressure sensor circuit (Alarm 3420). This is a serious severity code.
- DIY difficulty
- moderate
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Common Symptoms
- Alarm 3420 shown on the Xc-series controller display
- Machine may shut down or refuse to load, depending on the alarm class
Probable Causes (Ranked by Likelihood)
- The condition named by the alarm: Pumper oil pressure sensor circuit High
- Sensor, switch or wiring fault in the monitored circuit producing a false alarm Moderate
Frequently Asked Questions
What does Atlas Copco alarm 3420 mean?
On the Xc-series controllers that use it (Xc4004), alarm 3420 is: Pumper oil pressure sensor circuit.
How is the severity on this page decided?
Atlas Copco's published alarm table names each alarm but does not grade severity, so the rating here is inferred from the alarm's function (shutdown-class alarms rated higher than warnings and service reminders). Treat any alarm that stops the machine as serious regardless of the label.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
Identify which Xc-series controller your machine has FIRST (Xc1004, Xc2003 or Xc4004 — it is named on the controller face or in the machine documentation). The same alarm number can mean different things on different controllers, so the controller identity is part of the diagnosis.
On Xc4004: alarm 3420 = Pumper oil pressure sensor circuit
Stop the machine and check the oil level before anything else. Do not keep restarting against a possible real loss of oil pressure — if the level is correct, verify the switch/sensor and its wiring before condemning anything expensive.
A circuit alarm means the controller lost a plausible signal — check the sensor connector and wiring for damage or corrosion before replacing the sensor itself.
This page is built from Atlas Copco's published Xc-series alarm table (linked below). For machine-specific procedures, use the manual for your exact unit — the table defines what the alarm is, not every model's repair steps.
Sources 1
This page is built from documented references. Verify against your own service info before repair work.
- Atlas CopcoXc-series controller alarm code table (official Atlas Copco Power Technique publication covering Xc1004, Xc2003 and Xc4004 controllers)
Commonly Affected Vehicles
- Atlas Copco portable compressors with Xc1004, Xc2003 or Xc4004 controllers (XAS and related series)
Related Codes
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