Furukawa HCR1000-DS2 / EDSII Fault Code Guide — Every Code, With Fixes
A reference for technicians and machine operators — by S.Suvit Trading, Furukawa specialists since 1968
Why reading the codes matters
Furukawa drills fitted with a touchscreen (HCR1000-DS2, EDSII and related models) have a warning system called the Information Display, which shows an English message whenever a sensor detects a problem.
The problem is that the screen tells you "what is wrong" but not "what to do about it." So many technicians see a code and guess — or worse, silence the alarm and keep working.
This article compiles every code from the Furukawa factory manual (document EL405-D25) along with the causes and remedies the factory specifies — a data set published nowhere else, in Thai or English.
⚠️ Which models this applies to: this article covers machines with a touchscreen (NSJ) — HCR1000-DS2 and EDSII only. The plain DS with relay logic and an Omron ZEN has no such screen and no equivalent fault-code system.
How to reach the fault code screen
Codes pop up automatically on the main screen when an event occurs. To view them retrospectively:
Main screen → press MENU → TROUBLE SHOOTING → choose one of:
ENGINE FLASH CODE HISTORY — engine fault code history
FMMS HISTORY — machine warning history (Information)
INPUT TEST — live input signal status (used when tracing a cause)
On the history screens, red = occurring right now · blue = occurred previously and cleared. Tap a line to see detail.
Reading the screen: two sets of numbers you must understand
Each code carries two numbers, and they mean different things:
Number | What it is | What it's for |
Information No. (e.g. 101, 108) | The sequence number of the warning message | Use it to look up the tables in this article |
Check L/O No. (e.g. 3300.00) | The actual signal address in the PLC | Use it to trace the real wire and sensor |
The Check L/O No. is the key — the number before the dot (3300 / 3303 / 3304) is the signal channel, and the number after the dot is which bit within that channel. Once you have it, a technician can open the machine's I/O table and go straight to the wire number and the physical sensor.
Complete code tables
Group 1 — Engine and basic systems
No. | Screen message | Meaning | Cause / remedy | Check L/O |
101 | CHARGE | Charging voltage insufficient | No charging signal from the alternator → check alternator, fan belt, relay (ENR1) | 3300.00 |
103 | COMP. AIR TEMP (H) | Discharge air temperature abnormal → emergency relay stops the engine | Check compressor oil quantity and quality; check receiver tank and compressor piping for oil leaks | 3300.05 |
108 | HYD. OIL LEVEL | Hydraulic oil low → emergency relay stops the engine | Check for hydraulic oil leaks, top up oil | 3300.06 |
110 | AIR CLEANER | Engine air cleaner clogged | Clean or replace the element, check the sensor | 3300.04 |
111 | COMP. AIR CLEANER | Compressor air cleaner clogged | Clean or replace the element, check the sensor | 3300.01 |
114 | HYD. OIL FILTER | Hydraulic return filter clogged | Replace the return filter element | 3300.03 |
Group 2 — Control system (I/O Unit)
No. | Screen message | Meaning | Cause / remedy | Check L/O |
121 | I/O UNIT 1 ERROR | I/O unit no. 1 faulty | Unit failed or communication line fault → inspect/replace unit, check for broken wiring and connectors | 1520.01 |
122 | I/O UNIT 2 ERROR | I/O unit no. 2 faulty | As above | 1520.02 |
123 | I/O UNIT 3 ERROR | I/O unit no. 3 faulty | As above | 1520.03 |
137 | PC BATTERY IS ABNORMAL | PLC (sequencer) backup battery dead | Replace the battery | A402.04 |
Group 3 — Rod changer
No. | Screen message | Meaning | Cause / remedy | Check L/O |
132 | ARM SWING IN ERROR | Arm swing-in did not complete (stopped mid-cycle) | Switch ON for more than 5 seconds with no signal from the proximity switch → check switch position and function | 3304.09 |
133 | ARM SWING OUT ERROR | Arm swing-out did not complete | As above | 3304.08 |
134 | ROTATOR SWING IN ERROR | — | Not used (未使用) | — |
135 | ROTATOR SWING OUT ERROR | Rotator swing-out did not complete | Solenoid commanded for 5 seconds with no signal → adjust proximity switch position, check solenoid valve operation | 3304.10 |
136 | MAGAZINE ROTATION ERROR | Magazine will not stop rotating / wrong position | Check proximity switch position and function, check solenoid valve | 3304.07 |
138 | SWING IN INTER LOCK | Swing-in interlock | The drifter is ahead of the mid position, so swing-in is blocked → retract the drifter to the mid position or further back, check the mid-position proximity switch | 3304.11 |
Group 4 — Flushing air system
No. | Screen message | Meaning | Cause / remedy | Check L/O |
158 | FLOW SWITCH ERROR | Blow flow switch abnormal | Signal present from key-switch ON → check the switch, check wiring, replace the switch (side effect: auto-throttle operates whenever the compressor runs, and anti-jamming operates continuously) | 3300.02 |
159 | PRESSURE SWITCH ERROR | Blow pressure switch abnormal | Signal present from key-switch ON → check the switch, check wiring, replace the switch (side effect: anti-jamming operates continuously) | 3300.07 |
Group 5 — Proximity switch wire break (TROUBLE, NON-CONNECTION)
Every code in this group means the same thing: "proximity switch wiring broken or switch failed." The remedy is identical for all of them: check the proximity switch, and check the cable.
No. | Screen code | Which switch | Check L/O |
165 | CLS-PF | Feed forward detection | 3303.00 |
166 | CLS-PR | Feed backward detection | 3303.01 |
167 | CLS-PH | Actual drilling detection (本穿孔) | 3303.02 |
168 | CLS-FF | Feed rapid-forward detection | 3303.03 |
169 | CLS-FR | Feed rapid-backward detection | 3303.04 |
170 | CLS-AR | Magazine feed in/out position, rod indexing position | 3304.07 |
171 | CLS-ARO | Arm swing-out detection | 3304.08 |
172 | CLS-ARI | Arm swing-in detection | 3304.09 |
173 | CLS-RS1 / RS2 | Rotator swing-out detection | 3304.10 |
174 | CLS-MF | Drifter mid-position detection | 3304.11 |
Group 6 — Status messages (not faults)
No. | Screen message | Meaning |
160 | HYD. OIL HEAT | Hydraulic oil warming up (heat switch is on) |
161 | R/C HYD. OIL HEAT | Oil warming + rod changer hydraulic circulation running |
162 | R/C MANUAL OPERATION | Rod changer being operated individually (individual switch is on) |
Group 7 — Maintenance interval reminders (FMMS2 option)
No. | Screen message | Meaning |
140 | MAINTENANCE EVERY 50H | 50-hour service interval reached |
141 | MAINTENANCE EVERY 250H | 250-hour service interval reached |
142 | MAINTENANCE EVERY 500H | 500-hour service interval reached |
143 | MAINTENANCE EVERY 1000H | 1,000-hour service interval reached |
144 | MAINTENANCE EVERY 2000H | 2,000-hour service interval reached |
The five most important codes in depth
1. The CLS-xx group — "TROUBLE, NON-CONNECTION" ★ the most common
Why it matters: it is the most frequently seen group, and the group most often fixed the wrong way.
These codes mean "the proximity switch wiring is broken" — not that the switch failed to detect an object, but that the system cannot find the switch at all.
Real causes, in order of frequency:
Wire broken by vibration — proximity switches are mounted on the guide shell, rod changer, and carriage, all of which vibrate constantly while drilling, so cables fatigue and break at bend points
Loose connector or water ingress — drilling sites have both dust and water
Switch itself failed — from impact or heat
⚠️ Someone cut it out — some importers cut the sensor wiring so the machine "doesn't throw warnings," and never restore it to original
The correct way to check:
Go to INPUT TEST → CONTROL PANEL IN/OUT and watch the lamps on channels 3303 and 3304
A lamp with a red line beneath it = the wiring for that switch is broken (this is a specific meaning, not simply OFF)
Use the Check L/O No. from the table above to trace the wire number and the switch
Measure continuity from the control box through to the switch
What you must never do: do not "fix" this by cutting the wire or bridging the circuit so the light goes out. That is blinding the system, not repairing it — and it causes the rod changer to malfunction and do far more expensive damage
2. Code 103 — COMP. AIR TEMP (H) ★ stops the engine immediately
Why it matters: this is one of only two codes that command the emergency relay to shut the engine down immediately — the factory designed it that way because leaving it running risks severe compressor damage or fire.
What it means: the air temperature leaving the compressor is abnormally high.
What the factory says to check:
Compressor oil quantity and quality — low or degraded oil means it cannot carry heat away (use ISO VG32 only; never substitute VG46 hydraulic oil)
Receiver tank and compressor piping — check for oil leaks
Additional checks from our experience:
The compressor oil cooler clogged with rock dust
The oil separator element blocked — visible as a rising differential pressure
Whether the cooling fan is working properly
⚠️ Never simply restart and keep working without finding the cause. The system shut the engine down for a real reason.
3. Code 108 — HYD. OIL LEVEL ★ stops the engine immediately
Why it matters: the other code that shuts the engine down immediately, because if the hydraulic pump draws air it can be destroyed within minutes — and piston pumps are very expensive.
What it means: hydraulic oil in the tank has fallen below the safe level.
What the factory says to check: inspect for hydraulic oil leaks, then top up the oil.
The point most people miss: topping up and carrying on without finding the leak is treating the symptom. Oil does not disappear by itself — you must find where it is going.
Common leak points: hydraulic hoses at the guide shell and boom (the parts that move constantly) · feed cylinder seals · fittings loosened by vibration · travel motor seals
And when you do top up — always filter the oil first, because new oil from the drum is typically dirtier than the cleanliness the system requires (ISO 4406 = 16/14/11).
4. Code 137 — PC BATTERY IS ABNORMAL ★ cheap to fix, expensive to ignore
Why it matters: this is the easiest and cheapest code to fix, and the one most often ignored, because the machine keeps working normally.
What it means: the PLC (sequencer) backup battery is dead.
The manual's remedy: replace the battery.
Why you must not leave it: this battery backs up the PLC's data and settings. If it drains completely and the power then goes off, some settings can be lost — and recovering those is far harder than replacing a battery.
Recommendation: if you see this code, replace the battery that week. Don't wait for the next PM interval.
5. Code 101 — CHARGE ★ ignore it and the machine dies on site
Why it matters: if this appears while the engine is running, the battery is not being charged. Keep working and the battery will go flat, the machine will stop on site, and it will not restart.
What it means: no charging signal from the alternator.
Three things the factory says to check:
Alternator — worn brushes, failed diodes, or an open winding
Fan belt — loose or slipping, so the alternator is not driven hard enough (check tension: press midway between the fan pulley and the alternator with 98 N of force; deflection should be 7–10 mm)
Relay ENR1
The order to check in: always start with the belt, because it is the easiest to inspect and a common cause. Then measure charging voltage at the battery terminals with the engine running (roughly 27–28 V for a 24 V system). If it is lower than that, move on to the alternator.
Messages that are NOT faults — don't panic
These three are status messages telling you what the system is doing, not damage:
160 HYD. OIL HEAT — hydraulic oil is warming because the oil-heat switch is on
161 R/C HYD. OIL HEAT — oil warming and rod changer hydraulic circulation running
162 R/C MANUAL OPERATION — the rod changer is being operated individually because the individual switch is on
And one more that is often mistaken for a breakdown:
138 SWING IN INTER LOCK — this is a safety system, not a failure. The system refuses swing-in because the drifter is still ahead of the mid position. The fix is to retract the drifter back to the mid position or further, then command swing-in.
When to stop the machine immediately
Stop at once and do not keep working when you see these:
Code | Reason |
103 COMP. AIR TEMP (H) | The system shut the engine down itself — the compressor is at risk of severe damage |
108 HYD. OIL LEVEL | The system shut the engine down itself — the hydraulic pump can fail within minutes |
121/122/123 I/O UNIT ERROR | The control system cannot communicate — the rod changer may malfunction |
114 HYD. OIL FILTER | A blocked filter means dirty oil bypasses straight into the pump |
Other codes allow you to keep working, but should be dealt with at the next PM interval.
Summary
Three things worth remembering:
The Check L/O No. is the key — it leads you to the actual wire and sensor, so you don't have to guess
The CLS-xx group means a broken wire, not a switch that failed to detect — and never "fix" it by cutting the wire to kill the light
Codes 103 and 108 shut the engine down themselves — the system isn't broken; it is protecting expensive components for you
A machine whose technician can read the codes gets repaired at the right point with little downtime. A machine whose technician guesses gets parts replaced one after another until something works — the difference is understanding the system, not owning better tools.
About this article
All fault code data in this article comes from the Furukawa factory manual, document EL405-D25 (Information Display Content) for the HCR1000-EDSII, and document EL405-D27 (Display Operation) — the additional guidance comes from our own service experience.
S.Suvit Trading Ltd., Parts has imported, overhauled, and serviced Furukawa hydraulic crawler rock drills since 1968. We provide control-system diagnostics, electrical repair, and restoration of sensor systems that have been cut out, back to original condition.
If your machine is showing a code you're unsure about, or was supplied with sensors removed by another importer, we're glad to advise.
S.Suvit Trading Ltd., Parts 704 Charoen Rat Road, Khlong San, Bangkok 10600 svtrade.com
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