Canon / TR4500 series

1203 - The paper output cover was opened during printing.

The paper output cover was opened during printing.

This guide is scoped to the TR4500 series family. Exact menu wording, cartridge naming, and service behavior can still vary by model variant and firmware.

Severity

Low

Most likely cause

The paper output cover was left open or opened during a print job.

Can you keep using it?

Often yes

Consumables involved

Paper output cover

Can you keep using it?

Can you keep using it?

Contact customer support if any of these apply

  • !1203 returns even though the cover is clearly shut.
  • !The cover hinge or latch no longer closes or sits normally.
If the printer still starts normally: This is often recoverable with the basic checks below, as long as the printer returns to ready without a deeper service warning.

What to check first

Step-by-step checks

  1. 1

    Consumable check

    Close the paper output cover fully.

    Start with the official recovery step before moving on to parts or deeper servicing.

  2. 2

    Consumable check

    Remove any visible paper that did not clear the path normally.

  3. 3

    Safe first step

    Retry with one small print job after the cover is fully shut.

Background

What this message usually means

Canon uses support code 1203 when the TR4500 series detects that the paper output cover was open during printing. This usually interrupts the print path and needs the cover closed before the printer can continue normally.

Before the message

What users usually notice first

Messages like this often appear after the printer fails one of its normal startup, supply, or paper-path checks and cannot return to ready state cleanly.

Diagnosis

Likely causes

Most common

The paper output cover was left open or opened during a print job.

Common

The cover was not seated fully before printing started.

Possible

The printer paused because the paper path was no longer in a normal state.

Service

When service or replacement is more likely

  • -This is a printer-state interruption, not a deeper printhead or service code.

Avoid wrong turns

Common misreads of this message

  • -Treating the message like a confirmed failed part instead of a support clue about which system has stopped the printer.
  • -Assuming no physical path issue exists just because no full sheet is visible at first glance.

See also

Related codes in this family

Explore more

More Canon printer families

Read this next

Helpful guides for this problem

Boundary

When to stop troubleshooting and move to support

Use the message once to classify the problem, then move to support if the printer still cannot return to ready after the first safe checks.

Keep browsing

Where to go next

Source notes

Canon's official 1203 page says the paper output cover is open and directs users to close it before continuing.

Built around Canon TR4500-series official support-code guidance. Exact wording can vary a little by regional model naming, but the support-code meaning stays close across the family.

Printer error codes can vary a little by firmware, region, and exact model variant. Use this guide as a family-level starting point and stop if the next step would require disassembly or service-mode changes.

Known family variants: TR4520, TR4522, TR4527, TR4530, TR4540, TR4550, TR4551, TR4560, TR4570, TR4570S, TR4580, TR4590, TR4595

Last reviewed: 2026-04-12

Reference: Open reference

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