Help with fault codes needed.

[Brian23]

Hi. I have been having an intermittent engine light for a while. It will turn on and off at any period of time. Sometimes nothing for months.
So I cleared the fault codes yesterday. Light out. Drove the car in the morning. Fine. On the way back, the light is back on.
Fault codes
P200A-000 x2
P2029-000
P2010-000

The only one I can find that is similar :-

P2000 NOx Trap Efficiency Below Threshold (Bank 1) Any help to find these appreciated.

Just found this. https://www.troublecodes.net/p2codes/p200a/#:~:text=OBD II fault code P200A is a generic,the PCM receives from engine and/or drivability sensors.

P200A – Intake manifold air control actuator / solenoid, bank 1 – performance problem​

P2029 – Auxiliary heater (fuel fired) – system disabled. What is this, as my car is petrol​

P2010 – Intake manifold air control actuator / solenoid, bank 1 -circuit high​

All Japanese to me. Any help appreciated.

 

[LostKiwi]

First question.
What are you using to scan for codes?
Some codes are able to have their meaning changed by the manufacturer (manufacturer specific codes). For those codes a simple Google search will often turn up the wrong description (P2029 is an excellent example).
Only a small subset of available codes have strictly defined meanings common across all manufacturers.
For example p2029 can be auxillary heater, engine rpm sensor, mixture too lean and so on, depending on what the manufacturer has assigned to it. Often a code will also have a secondary code (e.g P2029-001 which in some MBs points to crank position sensor).
P2029-002 on other hand points to a mixture formulation issue - a totally different area.

Second question:
What car is it (aside from 'E Class').
Kind of important to know as codes have different meanings between petrols and diesels for example.

 

[Brian23]

Hi thank you for reply. It is a 2005 E200 Estate. Petrol. I am using a Carsoft i980.

 

[LostKiwi]

Have you the latest updates on it?
I'm surprised it doesn't have description fields on those codes.

 

[Brian23]

Yes updated it last week, but it says that they are unknown.

 

[LostKiwi]

Hard to know.
Probably needs reading in a better code reader to get the correct description for those codes.

One suggestion a quick Google threw up is manifold air leak or MAF (I'm loathe to say MAF as people have a habit if throwing new ones on for no reason).

What other symptoms are you getting?

 

[Brian23]

Changed MAF last year because of this and yes, didn't cure it. The engine light comes on at any length of time from the last time it was on, whether on a motorway, where you feel nothing or at a stop at a junction or lights when you may get a split second stutter of the engine or on occasion a full uneven tick over for 5 seconds or so. The light will go out when it feels like it, a day or a week later and comes back on a day or months later, there is no pattern at all. I try to do my own mechanical fixes where possible, even though I am 65, but this is just an irritation, especially around MoT time.
As the car does not have great value and I do not want to take it to Mercedes and spend more on it than the car is worth. lol.

 

[supernoodle]

Brian, in 2005 ISO 15031-6 was published which defined many codes and the faults they should be assigned to. P2029 is one such example. The definition you found on Google (Fuel Fired Heater Disabled) is the ISO norm.
As your car will have been homologated prior to this date they were free to assign the codes as they pleased. So don't always trust what you find on Google.

Even if you have a later car it's worth pointing out only certain codes are defined in the standard, there are ranges that are set as "Manufacturer controlled".

 

[LostKiwi]

Symptoms described can also be down to a sticking EGR. Worth checking.

 

[Botus]

Hard to know.
Probably needs reading in a better code reader to get the correct description for those codes.

One suggestion a quick Google threw up is manifold air leak or MAF (I'm loathe to say MAF as people have a habit if throwing new ones on for no reason).

What other symptoms are you getting?

... my sisters Focus has just been miss-firing like a dog and smelling of petrol fumes after just seconds of starting - I stuck my scanner on it and got MAP sensor - and I did just as you have written - thought here we go - then realised it said MAP not MAF (its got a turbo and has both - the MAP was only 40 quid but rather than fix it they have binned the car so won't know - oddly when I looked it up seems its normal for this to cause Cyl 2 to massively over fuel - I guess so you do go to ford and hand over 400 quid for a 60 second job

not relevant to this Merc fault other than agreeing with LostKiwi, lots fit a MAF and it doesn't fix anything

 

[Brian23]

Symptoms described can also be down to a sticking EGR. Worth checking.

Thank you. Looking at this. https://www.bing.com/videos/search?...20211%20egr%20repair&sc=0-23&sk=&cvid=E27F981

it seems that it does not have a vacuum line to it. Is this one driven by the ECU or is there a vacuum line somewhere?

 

[LostKiwi]

If it's ECU driven it won't be sticking as the ECU monitors it.

 

[Brian23]

If it's ECU driven it won't be sticking as the ECU monitors it.

I will have to look on the actual car. I suppose a clean would not harm it.

 

[Brian23]

Symptoms described can also be down to a sticking EGR. Worth checking.

I found the EGR, it is vacuum driven, so I used a brake bleeder to put a vacuum on it, and it held the pressure and you could hear it snap closed when the pipe was quickly removed and the vacuum was released, so not that.