EMS light on - VCDS Lite results

the_luton_man

the_luton_man

Member
United-Kingdom
Hope I can be guided towards what to do next. The EMS yellow light came on . The second time in the last couple of months, both times after the miserable days of rain we have been having for months, and on both occasions having only driven less than a mile from home.

I installed a new coil pack in December to my 1.4 SE Petrol Model Year 2002. The old one was original but seem to be deteriorating through age, so though a new Bosch coil pack would last another another few decades. My mileage below is genuine, I have only ever had the car serviced at A2 Cars and B&F. I was hoping I could limp along until the end of May to get it to B&F, however now think I should take it my local garage who may not know about A2's so I was hoping to give them some information to go on.

Note - I only scanned the Engine Controller this morning, all the others were scanned recently and had no faults I used the Gendan cable and had to set the baud rate to 9600 to read the engine controller.

VCDS-Lite
Windows Based VAG/VAS Emulator
Version: Release 1.2
www.Ross-Tech.com
Workshop Code: 000 00000
Diagnostic Trouble Code Report
Monday, 29 April 2024, 11:06:57.
VIN Number:
Mileage: 51467 Repair Order:
Control Module Part Number: 036 906 034 EG
Component and/or Version: MARELLI 4MV G 4030
Software Coding: 00051

6 Faults Found:
16684 - Random/Multiple Cylinder Misfire Detected P0300 - 35-10 Intermittent
16685 - Shareware Version. To Decode all DTCs P0301 - 35-10 Please Register/Activate - Intermittent
16686 - Shareware Version. To Decode all DTCs P0302 - 35-10 Please Register/Activate - Intermittent
16684 - Random/Multiple Cylinder Misfire Detected P0300 - 35-00
16685 - Shareware Version. To Decode all DTCs P0301 - 35-00 - Please Register/Activate
16686 - Shareware Version. To Decode all DTCs P0302 - 35-00 - Please Register/Activate
Readiness: 0010 0001
 
Misfires in cyl 1 (16685) and 2 (16686). Could it be plugs or plug leads?

edit: if it has happened in the rain, check the hood drains. sometimes a drop of water is enough to shorten the plug and let it misfire, bringing on the eml. I had this once happen to me in the rain, because I lost a rubber nozzle on the drain above plugs/alternator.
 
Miss fires are, most likely, down to electrics. Your miss fires are, predominantly on cylinder 1 & 2, (P0301 & P0302).
As you've replaced the coil pack, I suggest you replace the HT leads next.
Then clear the fault codes, so that you can clearly see any improvements 🤞
I'm guessing that the spark plugs are relatively new, as it seems the car is regularly serviced, if this is not the case then replace them too, NGK, Bosch, Denso are good quality.
Good luck.
Mac.
 
I concur with all the suggestions above. The fact that it is adjacent cylinders, in rainy conditions would have me immediately wondering if water is dribbling onto the engine at that end - in this case the cambelt end of the engine. Is the drain by the wiper pivots connected to the corrugated pipe that takes water down to the underpan or is this pipe absent? For that matter, is the scuttle panel intact or cracked there - I've had at least one where it had become brittle and rainwater was able to bypass the drain hole and enter the rear of the engine bay.
 
Robin_Cox said:
I concur with all the suggestions above. The fact that it is adjacent cylinders, in rainy conditions would have me immediately wondering if water is dribbling onto the engine at that end - in this case the cambelt end of the engine. Is the drain by the wiper pivots connected to the corrugated pipe that takes water down to the underpan or is this pipe absent? For that matter, is the scuttle panel intact or cracked there - I've had at least one where it had become brittle and rainwater was able to bypass the drain hole and enter the rear of the engine bay.
Click to expand...
They are also, I think, a pair of cylinders that share a spark, (the AUA fires two cylinders at the same time, 1 & 2, and 3 & 4), so a dodgy lead on either 1 or 2, (or 3/4), will probably affect it's twin.
Mac.
 
Many thanks to all. I took the bonnet off and the attached sycamore seed had lodged where I think rainwater should have been draining from the bonnet. I then took out each of the HT leads, they looked pretty good but I will change them gor Bosch as they look like the originals so are now 22 years old. Plugs were all changed to NGK by Tony at A2 Cars at 48180 miles, my car is now on 51467. So I have done 3287 miles since they were changed in 2015, and though the NGK plugs are now 9 years ago I hope they haven't rusted. I next cleared on VCDS lite the DTCs and right now there is no yellow EMS lighr, even when I ran the engine to temperature. as suggested, I will look up on Ross Tech all codes, for now I just looked up the missfire ones. Didn't think I would be hoping for even more rain...but I lwill check to see if the removal if the sycamore seed has fixed the EMS light for now.

Again, thank you so much everyone...Tom
 

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All the DTCs are miss fires.
P0300 = Random miss fires, P0301 = Cylinder 1.
P0302 = Cylinder 2
P0303 = Cylinder 3.
P0304 = Cylinder 4.
Nothing else suspicious.
The DTCs could have been there for ages, anytime since last cleared.
It can be annoying, but it seems quite common not to clear DTCs, when a part is replaced, that is associated with those same DTCs.
Should be a basic routine, every time.
Mac.
 
Just now checked on Ross Tech and as you say @PlasticMac the DTCs are missfire related. So having initially jumped to assuming I needed to change the coil pack in December 2023 I will now change the leads. Probably should have done that when changing the coil pack, though I still have the old coil pack which is possibly not actually faulty, will nevet know! Tom. ..... ps Today is the first time I have used the Gendan cable since I bought it and downloaded VCDS lite. Now that I know my way round VCDS a bit I will diarise plugging in monthly as it is actually quite nice sitting in my A2 and I never seem to use it enough as I only ever drive 100 miles or less monthly.
 
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