Atlas Copco XAS 185: Why Won’t My Compressor Start? Common Fault Codes and Fixes
Nothing slows down a jobsite faster than a compressor that refuses to start. Your Atlas Copco XAS 185 is equipped with a control system that helps diagnose problems, but understanding these fault codes (and what to do about them) can get you back up and running faster. Here’s a practical guide to common no-start issues and their solutions.
1. Low fuel level or fuel system air lock
Low fuel or air trapped in the system can prevent the engine from starting or cause it to stall shortly after starting.
- Suggested action: Check and refill the fuel tank. Bleed the fuel system using the hand primer pump or bleed screw to remove any air pockets.
2. Low battery voltage
A weak or dead battery won’t provide enough power to crank the engine or operate the control system.
- Suggested action: Check battery voltage and connections. Charge or replace the battery if needed. Clean and tighten terminals to ensure a strong electrical connection.
3. Fault code: High coolant temperature
If the system senses an overheat condition, it may prevent restarting to protect the engine.
- Suggested action: Let the engine cool completely. Check coolant level in the overflow tank and top up as necessary. Inspect for leaks or blockages in the cooling system.
4. Fault code: Low oil pressure
Low oil pressure can trigger an automatic shutdown and block restart attempts.
- Suggested action: Check engine and compressor oil levels using the dipstick and sight glass. Top off as required. Inspect for oil leaks and address immediately.
5. Fault code: High soot load (DPF)
Excessive soot in the Diesel Particulate Filter (DPF) can limit engine operation or block restarts.
- Suggested action: Initiate a forced regeneration using the controller’s settings. Ensure the machine is in a safe area with good ventilation. If the code persists, a service regeneration may be needed. Consult a qualified technician.
6. Safety system interlock or emergency stop engaged
If the emergency stop button is pressed or a safety interlock is active, the compressor will not start.
- Suggested action: Verify that the emergency stop button is fully reset. Inspect safety switches and ensure all panels and doors are properly closed.
7. Electrical connection or ECU fault
Loose wiring or a fault in the electronic control unit (ECU) can interrupt startup.
- Suggested action: Inspect visible wiring for loose or damaged connectors. Check fuses and relays as indicated in the service manual. If no issues are found, consult a technician for advanced ECU diagnostics.
Final thoughts
Diagnosing start-up problems quickly keeps your Atlas Copco XAS 185 on the job and reduces downtime. Regular inspections, fluid checks, and attention to fault codes can help you fix many common issues without waiting for a service call.