Merlo Tech Talk: Diagnosing the Fault

Merlo Tech Talk: Diagnosing the Fault

On the dashboard of every Merlo is an area where a number of icons, representing different operational aspects of the machine, can be seen. After starting the machine, some icons will flash on, then off. Some will stay on.

Throwing a wrench

When lit, these icons represent current machine activity or they can represent issues that need to be addressed.

One such icon is the book with a wrench.

Its consistent illumination, similar to the check engine light on a car, indicates an issue that needs to be addressed for the machine to perform with optimized productivity.

To understand the issue that needs to be addressed, engage the Onboard Diagnostics. This function is found in the LCD located on the steering column.

There are three screens on this LCD that show operational aspects of your Merlo.

Screen overview: What you will see

Screen 1 (standard view) is the ‘every day’ screen, visible when the key is turned on, even if the machine is not engaged.

Screen 2 is the basic information screen: language, time, etc. to be set. Also, on this screen is where the maintenance hours reset is located.

Screen 3 The diagnostic screen where  error messages appear.

Turn the key one click to engage the LCD. It is not necessary to fully engage the engine. Screen 1 appears.

On the left of the steering column are two buttons:

  • checkmark/OK, and
  •  X (or similar depending on model).

After the machine is turned on:

  • Press the checkmark/OK button for approximately 5 seconds.
  • This will place you on Screen 2.
  • While on Screen 2, scroll to the lower right-hand corner to highlight the Next Page function. Select this function; hold the button.
  • Screen 3 appears.

Engaging the screens

 Checkmark/OK = SCROLL


The diagnostic screen. Finding answers

Set up like a spread sheet, each name/acronym on the left denotes a specific machine function. If there is an error in any system it will show up in the far right column.

Errors make themselves known by colored exclamation points or letter.

When you see an error icon, scroll to that row of information. Press the X to select that row of information.

Next, scroll down to the bottom of the screen and select NEXT PAGE. On this page is the error explanation by way of one, or a series, of three digit codes.

Color codes explained

The color of the codes matter.

  • GREY means an error occurred somewhere between the last time the machine was on and this current engagement.
  • RED and YELLOW indicate an error that is active and needs immediate attention.

With the name of the error source (here in green) and the error code(s) in hand, you need to contact the AMS-Merlo Service Advisory Team. They will research the error code and provide the corrective measures to be taken. or call during regular business hours 803-327-4949.

To back out from this particular screen, press and hold the CHECK button. On the next screen, scroll to EXIT.
Press X to complete the action.

Operational training on all Merlos is available.
Please call our office at 803-327-4949  or send an inquiry to

Share this post

Download the Merlo Big Book

Download this free PDF in our Document Library
Get stats and handling capacities for each machine in the Merlo lineup, when you download our Merlo Big Book.

Twenty pages of photos and features that will leave you convinced that Merlo makes BETTER MACHINES.

    Find a Dealer

    Fill out this form, and we will put you in touch directly with your local Merlo dealer and service provider.


      Become A Dealer


        Delivery Address

        Get a Quote

          GET A QUOTE

          Delivery/Pickup Location

          BuyRentRe-RentNot Sure
          AgricultureCement MixerCompactConstructionMaterial HandlingRoto