Search…
Sign in
All Technical Guides
🟢 Verified Technical Guide FieldTech

JLG 600AJ Deutz D2.9 L4 Engine Crank / No-Start Diagnostics

JLG·600AJ·Deutz D2.9 L4·Intermediate·1-2 hours·0 views
Ask AI About This Problem Community Discussion Report Incorrect Info

The Deutz D2.9 L4 tier 4 diesel engine cranks strong but fails to fire and run. This often stems from issues in the primary fuel delivery system, active fault-induced ECU shutoff, or a lack of communication between the JLG ground control module and the Deutz engine ECU.

Symptoms

  • Engine starter turns over at normal speeds, but no ignition occurs
  • Exhaust tailpipe produces zero smoke during crank cycles
  • Handheld analyzer shows 'No Engine Communication' or ECU connection faults
  • Engine starts briefly (1-2 seconds) and then instantly stalls

Possible Causes

  • Clogged or air-locked fuel primary filter/water separator bowl
  • Defective electric fuel lift pump or failed 15A engine fuel pump relay
  • J1935 CAN bus communication drop between JLG GCM and Deutz EMR4 Controller
  • Lack of 12V switched ignition run signal at PIN 1.02/1.04 of the Deutz ECU harness

Diagnostic Procedure

  1. 1
    Verify Electric Fuel Lift Pump Operation
    Turn the keyswitch ON. Listen for the buzzing sound of the electric fuel lift pump located near the fuel tank. Measure voltage (12V) at the electric fuel pump connector. If voltage is present but the pump does not operate, replace the lift pump.
  2. 2
    Check Fuel System Air Ingress
    Inspect the clear bowl of the fuel pre-filter for bubbles or air pockets. Open the bleeder screw on the secondary fuel filter housing and cycle keyswitch to purge air out. Look for cracked fuel lines.
  3. 3
    Measure CAN Bus Signal Continuity
    Using any digital multimeter, check resistance across CAN-High and CAN-Low lines (Pins 6 and 14 of OBD diagnostic interface or corresponding GCM terminals) with the battery disconnected. It must read approximately 60 Ohms.
  4. 4
    Analyze Deutz EMR4 Engine Diagnostic Flash Codes
    Read active fault codes using either a Deutz-compatible diagnostic tool or by decoding the blink light pattern displayed next to the engine bay module. Identify safety stop/derate triggers.

Common Repairs

  • Replacing the Deutz electrical primary fuel lift pump
  • Replacing clogged primary/secondary fuel filter elements
  • Repairing chaffed engine harness wires leading to the J1939 CAN network terminals

Safety Precautions

  • Ensure engine bay is properly ventilated during excessive diesel cranking
  • Never use starting fluid (ether) on modern common-rail electronic Deutz engines

Required Tools

  • Deutz Engine Serial Diagnostic Tool (DECOM)
  • Digital Multimeter (DMM)
  • Fuel Pressure/Vacuum Test Gauges
  • Fuel Bleeding Kit

Related Fault Codes

SPN 639 FMI 9 (CAN Bus Communication Fault)SPN 1079 FMI 3 (Sensor Supply 5V Voltage High)

People Also Ask

  • What causes SPN 639 FMI 9 on a JLG boom lift?
  • Why is my Deutz D2.9 engine cranking but not producing smoke?
  • How do you troubleshoot a Deutz EMR4 ECU with no communication?
  • What can cause a 5V sensor supply high fault (SPN 1079 FMI 3) on Deutz engines?
  • Where is the Deutz D2.9 engine main relay located on a JLG 600AJ?
  • Why does my JLG Deutz engine start for 1 to 2 seconds and then shut representation?

Related Guides

JLG 600AJ Out-of-Level Alarm and Tilt Sensor CutoutJLG 600AJ Charging System Failure and Low Voltage FaultsJLG 600AJ Sluggish or Intermittent Boom Elevator FunctionsJLG 600AJ No Power at Ground Control Console (ADE System Diagnostic)JLG 600AJ Platform Footswitch Interlock MalfunctionJLG 600AJ Poor Drive Performance or Weak TorqueJLG 600AJ Oscillating Axle Lockout Valve DiagnosticsJLG 600AJ Front-Wheel Drive Steering Drift or Unresponsive Steering

Suggested Follow-Up Guides

  • Step-by-Step Deutz EMR4 ECU Pinout and Voltage Reference Troubleshooting Guide
  • JLG 600AJ Deutz D2.9 L4 Fuel System Primary to Secondary Pressure Diagnostics
  • How to Test and Locate CAN Bus Open and Short Circuits on JLG Boom Lifts
  • JLG 600AJ Sensor 5V Reference Circuit A & B Engine Diagnostics
  • Deutz D2.9 L4 Common Rail Pressure Control Valve Replacement Manual

Topics

JLG 600AJ Deutz D2.9 no startDeutz D2.9 SPN 639 FMI 9JLG boom lift no engine communicationDeutz D2.9 L4 crank no startDeutz SPN 1079 FMI 3 diagnosticJLG 600AJ ECU power supply troubleshootingDeutz EMR4 CAN bus troubleshootingJLG 5V sensor reference voltage faultDeutz D2.9 engine starts then stalls JLGJLG 600AJ Deutz engine diagnostic codes

Related Repair Cases

Loading…

Community Comments

Sign in to join the discussion.

Loading comments…

This educational guide was curated by FieldTech to help technicians diagnose common failures. Always follow manufacturer service manuals and safety procedures.