We can help diagnose fault C1020, C1021 on your Mercedes vehicle

A1 Diagnostics have all the latest Mercedes equipment and technology needed to diagnose fault codes. Fault codes such as C1020, C1021 in Mercedes vehicles and cars can be fully repaired from our garage workshop pictured below.

When you experience a fault like C1020, C1021 with your Mercedes vehicle you will get a fault code. This fault code will then explain what the symptoms are and what you need to do to service the vehicle. This month we are going to be looking at Mercedes vehicle fault codes and we start off with C1020, C1021.

Mercedes Fault Code: C1020, C1021

The C1020, C1021 is a MERCEDES-BENZ fault code and is related to the purge flow sensor circuit, the specific nature of the fault code is shown below.

• C1020 CAN Communication Fault
• C1021 CAN Communication With EA/CC/ISC Control Module Interrupted

What are causing these fault codes to be displayed are listed below.

• Faulty Left Rear Wheel Speed Sensor
• Left Rear Wheel Speed Sensor harness is open or shorted
• Left Rear Wheel Speed Sensor circuit poor electrical connection
• Faulty Anti-Lock Brake System (ABS) Module

Any of the points raised above can be why the C1020, C1021 fault code is being displayed, your Mercedes vehicle will need immediate assistance to avoid any further damage to the car.

We have Mercedes mechanics with over 20 years’ experience servicing C1020, C1021 fault codes

The C1020, C1021 fault code is a common occurrence. The C1020, C1021 we can diagnose and fix quickly and reliably. We have mechanics that can fix the C1020, C1021 fault code that have over 20 years’ experience working in our Mercedes garage, so, when you leave your Mercedes vehicle with us it is in safe hands.


When you experience a C1020, C1021 fault you will need a garage with all the latest vehicle technology to service and repair the fault. A1 Diagnostics have all the technology needed to ensure your Mercedes vehicle is serviced reliably at the most affordable prices.

If you have any queries or experience a Mercedes fault code get in touch and let us look at your vehicle and we will get you back out on the road quickly and efficiently.

Contact A1 Diagnostics

Get in touch today for expert advice or to book your vehicle in for an appointment we are happy to help you with any queries you have.

64 Sloper Road
CF11 8AB

Tel: (029 20) 220380
Fax: (029 20) 223172

Opening Times

Mon – Fri: 8:00am – 6:00pm

Email: info@a1-diagnostics.com