JLG Fault Codes — Complete Guide & What They Mean | EWP Spares Australia

If you work on JLG elevated work platforms, you've seen the flashing fault codes. Understanding what they mean is the difference between a 10-minute fix and an unnecessary call-out. This guide covers the most common JLG fault codes, what triggers them, and what to do about it.

 

⚠️ Note: This guide covers JLG boom lifts and scissor lifts with CAN bus control systems. Fault code behaviour may vary by model series and software version. Always refer to your machine's service manual for definitive guidance.

 

How JLG Fault Codes Work

JLG machines use an onboard diagnostic system that monitors inputs and outputs across the control system. When the system detects a fault — a sensor out of range, a short circuit, a communication error — it logs a fault code and typically restricts or shuts down operation to protect the machine and operator.

Fault codes are displayed on the platform and/or ground control panel display. On newer machines with CAN bus systems, the JLG Diagnostic Analyzer (part number 1001249695) connects directly to the machine and gives you real-time fault data, historical logs, and system parameters — invaluable for field diagnosis.

 

Reading JLG Fault Codes

Most JLG machines display fault codes as a two or three digit number, sometimes preceded by a letter (e.g. E, F, or a flashing sequence). The format varies by model series:

•       Older machines: flashing LED sequences on the control panel

•       Newer CAN bus machines: numeric display on the TCON or platform panel

•       With the JLG Analyzer tool: full code description, system data, and fault history

 

Common JLG Fault Codes — Boom Lifts

The following codes are commonly seen on JLG 400S, 450A, 600S, 800S, 860SJ, 1200SJP, and similar boom lift models:

 

Code

Description

What to Check

1-1

Drive enable fault

Check drive enable relay and wiring. Common cause: loose connector at the TCON.

1-2

Lift enable fault

Lift circuit not enabling. Check lift relay, inspect wiring harness for damage.

2-1

Low battery voltage

Charge batteries. If persists after full charge, test battery pack — cells may be failing.

2-2

High battery voltage

Charger fault or overcharge condition. Disconnect charger and test output voltage.

3-1

Boom angle sensor fault

Sensor out of range. Inspect angle sensor wiring and connector. May require sensor replacement.

3-2

Telescope sensor fault

Telescope position sensor failure. Check sensor mounting and wiring.

4-1

Platform overload

Platform load exceeded rated capacity. Remove load. If occurs without overload, check load cell calibration.

4-2

Tilt fault

Machine on excessive slope. Move to level ground. If on level surface, check tilt sensor calibration.

5-1

CAN bus communication loss

CAN network fault. Check all CAN connectors and wiring. Use Analyzer to identify which node has dropped.

5-2

TCON communication fault

Ground control module not communicating. Check TCON wiring harness and ground connections.

6-1

Pump motor fault

Pump motor over-temperature or overload. Let machine cool. Inspect motor brushes and connections.

6-2

Drive motor fault

Drive motor fault. Check motor connections, inspect for mechanical binding in drive system.

7-1

Emergency stop active

E-stop pressed or faulty. Check all E-stop buttons. Clean contacts if machine has been inactive.

7-2

Footswitch fault

Platform footswitch not detected. Check footswitch wiring and switch operation.

8-1

Turntable rotation sensor fault

Rotation sensor out of range. Inspect sensor and wiring.

8-2

Outrigger not deployed

Outriggers not correctly set. Re-deploy outriggers fully. Check outrigger sensors.

 

Common JLG Fault Codes — Scissor Lifts

Codes commonly seen on JLG ES1530, ES1932, ES2032, 2030ES, 2646ES, 3246ES, and similar electric scissor lift models:

 

Code

Description

What to Check

1

Low battery voltage

Charge batteries fully. If voltage doesn't recover, test individual cells.

2

Tilt fault

Machine tilted beyond limits. Level the machine. On level ground, check tilt sensor and calibration.

3

Platform overload

Reduce platform load to within rated capacity. Check load sensor if fault occurs without overload.

4

Emergency stop active

Check all E-stop buttons are released. Clean contacts.

5

Lift limit switch open

Lift limit switch not returning to rest position. Inspect limit switch and wiring.

6

Pothole protection fault

Pothole protection not returning to travel position. Check mechanism for debris or damage.

7

Drive enable fault

Drive not enabling. Inspect drive relay and enable wiring.

8

Lift motor fault

Over-temperature or overload. Allow cooling. Check motor brushes and connections.

9

TCON fault

Control system fault. Use JLG Analyzer to read full fault data. Check all CAN wiring.

 

Step-by-Step Fault Diagnosis Process

When a fault code appears, follow this process before replacing any parts:

•       1. Record the code. Note the exact code and any operating conditions at the time (cold start, under load, mid-operation).

•       2. Check the basics first. Battery charge level, all E-stops released, footswitch engaged, machine on level ground.

•       3. Connect the JLG Analyzer. Part 1001249695 gives you the full fault description, not just a number. It shows active and historical faults and lets you monitor live sensor data.

•       4. Clear the fault and retest. Some faults are transient (e.g. a momentary low voltage spike). If it clears and doesn't return, monitor the machine.

•       5. Check wiring before replacing components. The majority of fault codes on older machines are caused by corroded connectors and damaged wiring, not failed components.

•       6. Replace the faulty component. Use OEM-compatible parts — incorrect specifications can cause new faults or damage the control system.

 

💡 Pro Tip: The JLG Diagnostic Analyzer (1001249695) is the single most useful tool for fault diagnosis on CAN bus JLG machines. If you're regularly servicing JLG equipment, it pays for itself quickly. Available from EWP Spares — fast dispatch from NSW.

 

When to Call for Help

Some fault codes indicate issues that require specialist attention:

•       TCON or ground module replacement — requires software configuration

•       Load cell calibration — requires calibration weights and procedures

•       CAN bus network issues across multiple nodes — systematic diagnosis required

•       Structural or hydraulic faults — safety-critical, do not operate until repaired

 

Need Parts?

EWP Spares stocks a range of JLG replacement parts including the JLG Diagnostic Analyzer, joystick controllers, limit switches, and more. Fast dispatch from NSW, Australia.

Browse our JLG Parts collection or contact us if you need help identifying the right part for your machine.

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