Affected models: Canon multifunction machines with fax — imageCLASS (MF series), i-SENSYS and imageRUNNER / imageRUNNER ADVANCE. Home PIXMA inkjets don't use this code.
What This Error Means
Canon words #003 slightly differently depending on how big your machine is, but it's the same underlying problem in both cases.
On the smaller imageCLASS and i-SENSYS machines, Canon's manual says the data volume was too large to send or receive. On the bigger imageRUNNER machines, Canon is more specific: the fax call ran past a built-in time limit of 64 minutes and was cut off.
Either way, think of it like a phone call that gets hung up on you because it went on too long. A fax is sent one page at a time down a phone line, which is slow — so a long document, or a document scanned at very high quality, can genuinely take over an hour to transmit. The machine won't sit on the line forever, so it stops and logs #003.
Worth knowing: this code appears in the job log or on a communication report, not usually as a flashing error on the machine. It's telling you a particular fax failed, not that the machine needs attention.
What Causes It
- Too many pages in one fax — the single most common cause. A 200-page contract sent in one go is asking a lot of a phone line.
- Resolution set too high — fine or photo-quality scanning multiplies the amount of data per page several times over. Text documents rarely need it.
- Large photos, dark scans, or heavy graphics — a page that's mostly black takes far longer to send than a page of typed text.
- On the receiving end, the sender did one of the above — if #003 shows up on a fax you were receiving, the problem is at their end, not yours. Canon's own advice for this case is to ask the sender to fix it.
- A poor or noisy phone line — worth mentioning because it makes everything above more likely: when the line is bad, fax machines drop to a slower transmission speed, so a document that would normally take twenty minutes can crawl past the limit. Canon doesn't list this as a cause for #003 specifically, so treat it as a possibility rather than a fact.
How to Fix It
Fix 1: Split the document and send it in batches
This is Canon's own first recommendation and it fixes most cases in a couple of minutes.
- Divide your stack into smaller batches — 20 to 30 pages each is a safe size.
- Send the first batch as a normal fax and wait for it to complete.
- Send the next batch to the same number.
Each batch is a separate fax as far as the machine is concerned, so none of them gets anywhere near the time limit. Check the send report after the last one — you want a successful result line for every batch, not just the final one.
Fix 2: Lower the resolution
For ordinary printed or typed pages this makes almost no visible difference at the other end, and it can cut transmission time dramatically.
On imageCLASS and i-SENSYS machines, Canon's stated path is:
Home screen → Fax → TX/RX Settings tab → Resolution → pick a lower setting.
On imageRUNNER machines the resolution control sits on the fax send screen, usually under the scan or send settings. Menu wording varies between models, so if it isn't where you expect, check the online manual for your exact model number.
Standard or normal resolution is fine for text. Save fine and photo for documents where small detail genuinely matters — signatures, small print, actual photographs.
Fix 3: If you were receiving the fax, contact the sender
There's nothing you can change on your machine to fix an oversized incoming fax. Ask them to either lower the resolution on their end or split the document into two or more parts and resend. That's Canon's documented answer for the receiving side.
Fix 4: Consider scanning to email instead
If you're regularly sending long documents and hitting this code, faxing is fighting you. Most of these machines can scan straight to an email address or a shared folder instead, which has no such time limit and takes seconds. Worth setting up once if the same 150-page report goes out every month.
Fix 5: Check the phone line
A long shot, but cheap to test. Pick up a handset on the same line and listen for crackle, hum or static. If the line sounds rough, or the fax also fails to other numbers, that's worth raising with your phone provider — and your dealer can lower the machine's fax start-up speed, which helps on poor lines.
If None of That Works
Contact Canon support or your service dealer if:
- Even a two-page fax to that number returns #003
- Every fax fails regardless of destination, size or resolution
- The code appears alongside other fax errors like #005 or #018, which together point at the line or the machine's fax board rather than your document
Have this ready when you call: your model number and serial number (label at the back or under the front cover), the exact code and any longer variant shown with it, the destination fax number and roughly how many pages you were sending, and whether the machine is still in warranty.
