Check Used Bobcat Fault Codes Before You Pay for the Machine
Used Bobcat fault codes may sit in Machine IQ, factory-connected on all Pro loaders, so ask the seller to show the record before you pay.
Table of Contents
Can you read a used Bobcat’s fault codes before you buy?
Yes. Ask the seller to let you read the machine’s codes, and any code history it keeps, before you pay. Sources are the machine’s own display, a Bobcat dealer, or the seller’s Machine IQ record. Match each code to the list for that serial number, since Bobcat’s list reuses some codes across products. A code gives you a question to ask, not a price.
Read it before you pay
Bobcat’s code list says codes occur when a machine controller detects a value outside an acceptable range. A code is the machine’s report, not the seller’s opinion.
At the machine now, or planning the visit?
At the machine now? Go to the next section. Planning the visit? Start at the codes worth asking about.
ℹ️ Safety Note: Reading codes means keying on a machine with hydraulics and lift arms. A dropping arm can crush, and a keyed-on machine can move. This is general understanding only: follow the machine’s Operation & Maintenance manual, and let a qualified Bobcat technician do anything beyond it.
Where to look for a used Bobcat’s code history
Three places can hold a used Bobcat’s codes.
Its own service-codes screen
Bobcat says its service codes exist to inform machine operators of fault conditions. Which screen shows them, and whether earlier codes are kept, varies by series, so use that serial’s Operation & Maintenance manual. First, look up the code list for your serial number.
A dealer scan-tool session
Ask a Bobcat dealer’s technician for a diagnostic-tool read and what it means for that serial.
The seller’s Machine IQ record
Machine IQ, Bobcat’s telematics service, lets owners view critical fault codes and hours in its mobile app. It comes factory-connected on all Pro loaders and is available on a range of other machines, so older machines may have no record. See how Machine IQ fault codes work, and if the machine is connected, ask to see the record.
⚠️ Hazard: NIOSH and OSHA both document skid-steer crush injuries. Never work or reach under a raised lift arm or boom. For anything beyond the display, follow the O&M manual and use a qualified Bobcat technician.
Bobcat-defined codes worth a dealer’s explanation
Every wording below comes from Bobcat’s own code list; none is inferred.
Bobcat’s own wording, list revised 10-20
| Code | Bobcat’s wording | Applies To | Buyer handling |
|---|---|---|---|
| M0415, M0515, M0715, M0815 | Engine oil pressure, hydraulic charge pressure, hydraulic oil temperature, coolant temperature: shutdown | M-Series loaders (M0515 loaders only); M0415, M0715, M0815 also excavators | Named “shutdown”: stop, dealer diagnosis |
| M8554, M8555 | DPF service regeneration required, contact dealer / DPF service required | M-Series loaders | Dealer diagnosis |
| M7839 | Hourmeter changed | M-Series loaders | Ask seller for the documented reason |
| M4028, M4228, M7423, M7497 | Wrong ECU detected / wrong DCU detected / main controller not programmed / main controller software updated | M-Series loaders | Dealer diagnosis |
Source: Bobcat Company, Diagnostic Service Codes list, revised 10-20, retrieved 2026-09-30. Scope: M-Series loaders S450–S850 and T450–T870, M-Series excavators E26–E85. The list says it was created in 2020 and points readers to Bobcat’s Machine Diagnostics page for current information. Confirm each row there.
Bobcat’s list does not say which codes an owner can service, so a buyer’s job is to record the code and ask a dealer. Some codes repeat across products, so match yours to the serial. One code is also not a verdict: the list notes that a drive-controller “interrupted power” code can follow software updates. See how Bobcat’s code formats differ.
⚠️ Hazard: A shutdown-named code means stop and have it diagnosed, not run the machine to see if it returns. A qualified Bobcat dealer technician should explain any such code before you pay.
Match the code history to the hours and the paperwork
Codes, hours and paperwork should tell one story.
Displayed hours vs the Machine IQ hours record
On a connected machine, Machine IQ reports operating hours, so compare that record with the machine’s hourmeter. Illustration only, with hypothetical numbers: 1,900 on the hourmeter against 2,400 in the record leaves a 500-hour gap to explain. No Bobcat-published mismatch tolerance was found, so none is set here.
Service invoices vs the code timeline
Ask for dated service invoices and check that repairs line up with the codes you were shown. Unexplained codes are questions for the dealer, not accusations.
🧮 Run the Numbers: Used Equipment Hour-Value Estimator, with the model, year, hours and condition.
If the seller won’t show the history
A refused read is missing information, and missing information can be priced or walked away from.
A refusal, or a blank history on a high-hour machine
If the seller won’t allow a read or show a Machine IQ record, treat the machine as unverified. Price that risk in, or walk away. A blank history on a high-hour machine is a question for a Bobcat dealer.
Paying a dealer to inspect first
Have a Bobcat dealer technician inspect it before you buy, and put that condition in writing. Ask your own attorney about contract terms.
✅ Do This: Ask the dealer technician what this series’ code screen can show, and what a blank history can and cannot mean for that serial.
What a clean code history can’t tell you
By Bobcat’s own definition, a code needs a controller to detect an out-of-range value, so a problem nothing monitors can sit behind a clean screen.
What controllers can and can’t see
NIOSH’s skid-steer alert describes a fatal incident where a lift-arm pivot pin was reported missing. It also warns about the consequences of bypassed interlocks. A clean history says nothing about parts like that.
Checks a code read replaces nothing for
⚠️ Hazard: Inspecting lift arms, pins and hoses puts hands near crush points and pressurized hydraulic fluid, which can inject through skin. Don’t check under raised arms or feel for leaks by hand. Have a qualified technician do the physical inspection, and read NIOSH and CPWR’s 2026 skid-steer toolbox talk.
If safety devices are disabled or removed, walk away.
After the read: what to check next
Once you have a code, the serial number decides what it means.
Match the code to your machine’s serial
Bobcat says the serial number helps in finding product recall and warranty information. Use it to pick the right code list, then read which Bobcat fault codes stop work. Check recall status on Bobcat’s recall page.
Keep a written record of the read
Write down the serial, displayed hours, each code and its wording, the date, and who read it.
Used Bobcat fault codes: common questions
1. Can you check fault codes on a used Bobcat before buying?
Yes. Ask the seller to let you read the codes and any code history, or ask a dealer to read them, before you pay.
2. Where do I find fault codes on a used Bobcat?
On the machine’s display, through a Bobcat dealer, or in the seller’s Machine IQ record if the machine is connected.
3. Does every used Bobcat have Machine IQ?
No. Bobcat says it is factory-connected on all Pro loaders and available on a range of other machines, so older machines may have no record.
4. What does M7839 mean on a Bobcat?
Bobcat’s list words M7839 as “Hourmeter changed” for M-Series loaders. Ask the seller for the documented reason and check it against service records.
5. Which used Bobcat fault codes mean shutdown?
Bobcat’s list words M0415, M0515, M0715 and M0815 as shutdown for oil pressure, charge pressure, hydraulic oil temperature and coolant temperature. Get a dealer diagnosis before buying.
6. Are Bobcat fault codes the same on every model?
No. Bobcat’s list repeats some codes across products, so match each code to the machine’s serial before reading its definition.
7. Does a clean code history mean a used Bobcat is safe to buy?
No. A code needs a controller to detect an out-of-range value, so unmonitored wear can hide behind a clean screen. Have a qualified technician inspect it.
8. What if the seller won’t let me read the codes?
Treat the machine as unverified: price that risk in or walk away, and ask a Bobcat dealer to inspect before you buy.
9. Should a dealer inspect a used Bobcat before I buy?
Yes, when the stakes justify it. A dealer technician can explain any code and inspect what a code read cannot. Put the condition in writing.
Before you sign
You’re deciding whether this Bobcat earns a dealer’s time. Read the codes, record them, and match each to the serial’s list before you negotiate. If a code stops you, which Bobcat fault codes stop work covers what comes next. Run the hours through the Used Equipment Hour-Value Estimator with model, year, hours and condition.
The one thing to hire out is a Bobcat dealer technician’s explanation of any shutdown-named code before you pay.
