# 16346 - Control Module - Rom Error what does this mean?



## happychappy (Feb 9, 2015)

Hi all

After scanning my car with an OBD eleven code reader yesterday for what I thought might be a brake fault (none found) a fault on the "control module" was highlighted.

I didn't manage to save the fault noted on the OBD eleven, but remembered that the original Ross Tech scan that my friend performed when I first purchased the car contained a similar fault:-

16346 - Control Module - Rom Error and after this it says - 014 Defective.

Any ideas what this means?

How do I rectify?

I have found this on the Ross Tech forum, but to be honest it's as clear to me as mud:-

https://forums.ross-tech.com/showthread ... rol-Module

We did try to erase the fault, but the OBD eleven couldn't shift it.

Any ideas what this (from RT forum) means:-

"If you do not have any problems with car or cluster just ignore this code.Most likely in past someone use low quality tool to add key and this will happen".

Thanks for any help


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## John949 (Apr 12, 2017)

Appologies if you know this already.

In order to confirm the integrity of the code in the ROMs (i.e. that they haven't failed or been inadvertantly changed) the system performs a calculation using the value at every memory location. This is often called a checksum; although some are more complex than simply adding all the values together and lookng at the remainder. The upshot of this is that if you change some of the data within the ROM (adaption, coding, tuning etc.) you must also calculate correctly what the new checksum will be and change that too. The inference from the comments in the linked thread is that your ROM has been modified with a tool that got the checksum wrong. Fortunately the ECU still seems to operate with an incorrect checksum so you could ignore it.

Clearing the fault will not work because the checksum error is still there. You might be able to clear it by writing some new data to the ROM and hoping that your tool will re-calculate the checksum from scratch and get it right. Completely re-loading the ROM should cure it but this is brown trouser stuff if you do't know what you are doing and you would need to get hold of the correct ROM image.

A remote possibility is that you really do have a ROM fault e.g. a bit stuck at 1 or 0. In this case a replacement ECU would be the likely solution.


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## happychappy (Feb 9, 2015)

HinJohn

Thanks for the reply, I sort of understand it.... 

So I guess we are talking the main (are their any others?) ECU?

I have a feeling that there may be an alarm fault, possibly battery, I need to check this out, but other than that I believe all is good, I am hoping this is not related.

The car drives and performs fine, from memory there was also a canbus fault and possibly something to do with the comfort settings.

I hope to purchase a code reader (in research stage at the moment) to gain a better knowledge of these faults.

Re-Reading the fault code on the picture is it suggesting that the fault code actually is immobiliser related?


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## SwissJetPilot (Apr 27, 2014)

You haven't already, you can read up on the alarm issue here. I think we'll be seeing more and more of these errors across the Forum as our Mk2's continue to get older and older -

https://www.ttforum.co.uk/forum/viewtop ... &t=1836515

Just for grins, I found this posted in another forum. Seems fitting since you're delving into VCDS codes. [smiley=computer.gif]

_Yesterday, I had a scare,
I saw a code that wasn't there.
But it was there again today,
I wish, I wish it'd go away..._

The original 'Antigonish' poem is by William Hughes Mearns -

_Yesterday, upon the stair,
I met a man who wasn't there.
He wasn't there again today,
I wish, I wish he'd go away..._


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## SwissJetPilot (Apr 27, 2014)

You might check the primary address and see if there's a way you can reset it. I say that based on my recent finding of how to reset the brake pad warning light in this YouTube video. Not sure if you can do this with an OBD-11...???


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## happychappy (Feb 9, 2015)

Good news!

Alarm is fine! Yahey!


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