Fiat 500 and Punto engine ECU causing misfire faults

Punto and 500 ECU misfire

Fiat 500 and Punto engine management ECU malfunction will commonly cause a loss of power and intermittent to constant misfire faults.

The engine management light will become constantly illuminated, and when performing diagnostic checks you will find one or more ignition coil, or cylinder misfire, fault codes stored in the ECU.


If you have these Fiat 500/Punto engine ECU misfire faults you may have been told that you require a new ECU from the manufacturer to resolve these issues. However not only will this need coding at an extra expense and only come with a short one-year warranty, but it will be prone to fail in the same manner. The manufacturing defect has not yet been rectified at factory level, meaning all replacements will fail at some point.


We have a better solution – test and rebuild of your existing engine ECU. Our in-house R&D team have identified the root cause of these issues and have developed a rebuild option that will engineer-out these problems so that the ECU will not fail again, all backed by our unlimited mile Lifetime Warranty. Better still, the ECU will be plug and play when you receive it back as all original programming is retained, all within 3-5 working days

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Common Failure symptoms:

  • Loss of power
  • Misfire
  • Engine management light


Common fault codes:

  • P0300 – Random Cylinder Misfire Detected
  • P0301 – Cylinder 1 Misfire / Ignition Failure
  • P0302 – Cylinder 2 Misfire / Ignition Failure
  • P0303 – Cylinder 3 Misfire / Ignition Failure
  • P0304 – Cylinder 4 Misfire / Ignition Failure
  • P0351 – Ignition Coil A Primary/Secondary Circuit Malfunction
  • P0352 – Ignition Coil B Primary/Secondary Circuit Malfunction
  • P0353 – Ignition Coil C Primary/Secondary Circuit Malfunction
  • P0354 – Ignition Coil D Primary/Secondary Circuit Malfunction


Affected Vehicles:

  • Fiat 500 (2007 – 2017)
  • Fiat Punto (2006 – 2015)

*This problem will also affect the Ford KA Mk II 2008 – 2016 as it shares this Fiat 500 automobile platform


* Can’t find your part number? Check our full engine ECU catalogue for Fiat 500 and Fiat Punto


How to diagnose P0115 - Engine Coolant Temperature Circuit Malfunction:



Test and rebuild:

Our bespoke testing rigs will test each Fiat 500/Punto ECU beyond operating parameters both before and after rebuild to ensure the ECU exceeds OEM standards. We only use higher rated than standard components when we rebuild these ECU’s so you can be sure that the faults will not return.



No need for coding, all original programming is retained.



Our test and rebuild processes are second to none, each stage of the process is subject to strict quality control measures which is reflected in our extremely low defect rate of 0.49% across all our services.



Lifetime unlimited mileage*


How do I get my unit rebuilt?

To pay for the rebuild click the Shop Now link above, select your part number and click: Get yours rebuilt.

Print the payment/booking confirmation email.

Package the Fiat 500/Punto engine ECU inside a sturdy box with plenty of packaging material (make sure you include your confirmation email in the box).

Send us your package by tracked courier (the shipping instructions are on the confirmation email).

Once received we will test, rebuild and return your ECU with an unlimited mileage lifetime warranty. (if your unit turns out not to be faulty then we will refund your payment less a small testing fee and return shipping)


What if I don’t want to pay up front?

This is not a problem, if you prefer this option then follow the following steps:

Fill in and submit this test form.

Print the booking confirmation email.

Package the Fiat 500/Punto ECU inside a sturdy box with plenty of packaging material (make sure you include your confirmation email in the box).

Send us your package by tracked courier (the shipping instructions are on the confirmation email).

Once received, we will test your unit and call you to advise on the outcome of testing, if your ECU is faulty and you choose to go ahead with the rebuild then we will take payment over the phone using a debit/credit card.

We will then rebuild your ECU and return it to you with an unlimited mileage warranty.

If you require further information regarding this Fiat 500 and Punto engine ECU then please contact us.

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Comments on "Fiat 500 and Punto engine ECU causing misfire faults"
Dalkey autos LTD says: 1/9/2021 2:36:57 PM
2010 fiat 500 with multiple Missfire engine ECU fault ?
ECU Admin says: 1/9/2021 5:29:21 PM
Hi – if your fault symptoms, fault codes and ECU part number match the information above then you may well have a faulty engine ECU
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