Canon MF657Cdw / MF655Cdw / MF651Cw: It Prints, but Does Not Scan — MF Scan Utility Says “Cannot communicate with the scanner”

Last Updated on 14.04.2026 by DriverNew

Applies to models: Canon MF657Cdw, MF655Cdw, MF651Cw.

If the multifunction printer prints without problems, but when you try to scan through MF Scan Utility you get the error “Cannot communicate with the scanner”, this does not mean the scanner is faulty. In most cases, the problem is related to remote scan mode, machine registration in Windows, network settings, or the wrong Canon package being installed.

How the problem usually appears

• the multifunction printer prints normally;
• MF Scan Utility starts, but scanning does not begin;
• the message “Cannot communicate with the scanner” appears;
• the error repeats every time you try to scan from the computer.

Why this happens

Printing and scanning do not use exactly the same communication path. So the machine may be able to print but still not be ready for scanning. For this Canon product line, the most typical causes are:

• the machine is not switched to [Remote Scanner] mode;
• for network scanning, the machine is not registered in MF Network Scanner Selector;
• the wrong network is being used or the network environment is not suitable;
• only the printer driver is installed instead of the full Canon package;
• Windows or security software is blocking the scanner.

Where to start

1. Close MF Scan Utility.
2. Restart the multifunction printer.
3. Restart the computer.
4. Then try scanning again.

If the error remains, continue to the next step.

Step 1. Switch the machine to [Remote Scanner] mode

This is one of the most common causes. To scan from a computer, the machine must be in remote scan standby mode.

1. On the printer control panel, open the [Home] screen.
2. Press [Scan].
3. Press [Remote Scanner].
4. Then return to the computer and try scanning again through MF Scan Utility.

If scanning works after that, the problem was that the machine was not automatically switching to the required mode.

Step 2. Enable [Auto Online]

Canon provides a separate setting that allows the machine to automatically go online for remote scanning without using the control panel each time.

1. On the printer control panel, open <Menu>.
2. Go to <Function Settings> → <Common> → <Scan Settings>.
3. Find <Auto Online>.
4. If it is disabled, set it to <On>.
5. Save the changes and test scanning again.

If this setting is enabled, you usually do not need to open [Remote Scanner] manually every time.

Step 3. If the machine is connected over the network, register it in MF Network Scanner Selector

For a network connection, installing the driver alone is not enough. Canon explicitly states that the machine must also be registered in MF Network Scanner Selector.

1. Look in the Windows notification area next to the clock.
2. Find the Canon MF Network Scanner Selector icon.
3. Click it.
4. Find your machine in the device list.
5. Select the check box next to it.
6. Click [OK].

After that, open MF Scan Utility again and test scanning.

Step 4. If the machine is connected by USB, do not look for MF Network Scanner Selector

This point is important so you do not go in the wrong direction. Canon separately states that if the machine is connected to the computer by USB, installing the software is enough for scanning. Registration in MF Network Scanner Selector is required only for a network connection.

If you use a USB connection, go straight to checking the installed Canon software.

Step 5. Check whether the correct machine is selected in MF Scan Utility

1. Open MF Scan Utility.
2. Check [Product Name] or [Scanner].
3. Make sure your machine is selected.
4. If several Canon devices are listed, select the correct one manually.

Sometimes, after reinstalling the driver, an old device entry remains in the system and the program tries to communicate with the wrong machine.

Step 6. Check whether the full Canon package is installed, not just the printer driver

This is a very common cause for this product line. Printing may work even when the scanner driver is missing.

1. Open the Start menu and find the Canon folder.
2. Check whether MF Scan Utility is listed there.
3. If the program is missing, or if it was installed separately without the full driver package, remove the current Canon installation.
4. Download the full driver package for MF657Cdw / MF655Cdw / MF651Cw from the official Canon website.
5. Install it again.

For this series, scanning requires not only MF Scan Utility, but also the installed ScanGear scanner driver.

Step 7. When reinstalling, allow Windows Firewall changes

If Windows asks for permission related to firewall changes or network communication during Canon installation, do not reject that request without a reason.

1. Remove the current Canon installation if it is already not working.
2. Run the Canon installer again.
3. If a Windows prompt appears, allow the firewall-related changes.
4. Finish the installation and test scanning again.

If that access is blocked, printing may continue to work while network scanning does not.

Step 8. Check <Use Dedicated Port>

For this Canon product line, the dedicated port is also used for scanning with MF Scan Utility.

1. On the printer control panel, open <Menu>.
2. Go to <Preferences> → <Network>.
3. Find <Use Dedicated Port>.
4. Make sure it is set to <On>.
5. If you changed this setting, restart the machine.

Step 9. Make sure network scanning uses IPv4

Canon explicitly warns that the scan function is not available when the machine and the computer are connected in an IPv6 environment. For network scanning, you need a normal IPv4 network or a USB connection.

If your network environment is non-standard, this point is worth checking separately.

Step 10. If the problem happens on only one computer, check the security software

If the same machine scans normally on another computer, but not on one specific PC, the problem is most likely not in the multifunction printer itself, but in Windows or security software on that computer.

1. If third-party antivirus or Internet security software is installed, temporarily test scanning without it.
2. If scanning works when the protection is disabled, configure exceptions for Canon software and then enable the protection again.

After the test, do not leave the computer permanently unprotected.

How to quickly tell where the problem is

• If the machine is connected by USB — first check the installed Canon package and the presence of MF Scan Utility and the scanner driver.
• If the machine is connected over the network — besides the driver, be sure to check [Remote Scanner], <Auto Online>, and registration in MF Network Scanner Selector.
• If printing works but scanning does not — the issue is usually not the connection itself, but the machine’s preparation for use as a scanner.
• If everything works on another computer — the cause is almost certainly Windows, the driver, or security software on one specific PC.

When to contact support

• you already switched the machine to [Remote Scanner] mode;
• you enabled <Auto Online>;
• for a network connection, you registered the device in MF Network Scanner Selector;
• you checked <Use Dedicated Port>;
• you reinstalled the full official Canon package;
• the error still repeats.

If scanning still does not recover after that, it makes sense to contact Canon support and specify immediately how the machine is connected: by USB or over the network.

Brief conclusion

For the Canon MF657Cdw, MF655Cdw, and MF651Cw, the error “Cannot communicate with the scanner” is usually caused not by scanner hardware failure, but by remote scan mode, network registration of the machine, or an incomplete Canon software installation. First, check [Remote Scanner], <Auto Online>, MF Network Scanner Selector, <Use Dedicated Port>, and the full Canon package with the scanner driver. In most cases, the problem can be resolved without service.