Intermittent engine management system fault - EML on

[osman]

Hi I did a bit of a drive on Saturday around 700 miles and this morning another 250 on the way home. After around 10 miles I had the flashing yellow coil indicator lamp that the manual refers to as an engine management fault . I then realised the van had lost power, had become spongey and lacked acceleration .

I drove home regardless as it was only really effecting acceleration I could still do 70 mph once it got moving . But was having difficulty on hills and pulling away at speed.

I could see the acceleration was never reaching higher than 2000 revs .
My foot down and not much happening !

(I've had this light come on before during some very wet weather but didn’t notice a drop in the ability to accelerate .)

anyhow close to home I stopped ,did a little shopping and upon restarting the van ..the fault had vanished and the engine was back to normal .. at this point I realised if I had just stopped when the light first came on and the noticeable lack of acceleration started I could have probably avoided the 240 miles of limping home !
( could this have damaged my engine ? I guess not as it was being limited )

so anyone have an idea what the hell is happening ? Obviously a fault is detected but why would switching the engine off and then restarting clear the issue ?
( a bit like restarting a computer ? An unknown bug )

I guess it detects a temporary fault and then limits the acceleration until the engine is restarted .. at which point it no longer detects an error and allows the engine to operate as normal .
If this is the case does anyone know a likely cause for this intermittent and annoying error ?

 

[DXX]

It went into ’limp mode’ which allows you to get to a safe place or home.
If you want to know what the issue is that caused it you‘ll need to read the fault codes from the OBD2 port.
Well worth buying a Carista package as a garage will charge to get the same codes.

CARISTA OBD2 Bluetooth Adapter and App: Diagnose, Customize and Service your VW, Audi, SEAT, Skoda, Nissan, Infiniti, Toyota, Lexus, BMW, Mini : Amazon.co.uk: Automotive

Buy CARISTA OBD2 Bluetooth Adapter and App: Diagnose, Customize and Service your VW, Audi, SEAT, Skoda, Nissan, Infiniti, Toyota, Lexus, BMW, Mini at Amazon UK. Free delivery on eligible orders.

www.google.com

 

[osman]

It went into ’limp mode’ which allows you to get to a safe place or home.
If you want to know what the issue is that caused it you‘ll need to read the fault codes from the OBD2 port.
Well worth buying a Carista package as a garage will charge to get the same codes.

CARISTA OBD2 Bluetooth Adapter and App: Diagnose, Customize and Service your VW, Audi, SEAT, Skoda, Nissan, Infiniti, Toyota, Lexus, BMW, Mini : Amazon.co.uk: Automotive

Buy CARISTA OBD2 Bluetooth Adapter and App: Diagnose, Customize and Service your VW, Audi, SEAT, Skoda, Nissan, Infiniti, Toyota, Lexus, BMW, Mini at Amazon UK. Free delivery on eligible orders.

www.google.com

I have Carista but the fault codes made no logical sense to me , nothing that told me what could have caused the issue.

 

[mmi]

I have Carista but the fault codes made no logical sense

Could you please share the codes? Or perhaps even "Detailed ECU info"-report (under Service menu).

 

[osman]

Could you please share the codes? Or perhaps even "Detailed ECU info"-report (under Service menu).

Unfortunately I just reset them without thinking about it .. duh
I will now have to wait until the issue arises again and this time i will certainly do just that !
I will also remember to just trie restarting the engine instead of driving 200 miles in limp mode .. duh
I will check to see if there is a detailed ECU info report .

 

[osman]

Could you please share the codes? Or perhaps even "Detailed ECU info"-report (under Service menu).

Unfortunately as I reset the codes there is no information here that I can see Looks like I will have to wait to see if the fault occurs again

DETAILED ECU INFO

ECU info obtained with Carista 610099 for iOS:

VIN: WV1ZZZ7HZGH081656

Engine
Part #: 03L906019GQ
Component: R4 2,0L EDC
Software version: 8440
ASAM/ODX identifier: EV_ECM20TDI01103L906019GQ
Coding: 01194012232401080000 (hex)
[No fault codes]

ABS
Part #: 7E0907379P
Component: ESC
Software version: 0132
ASAM/ODX identifier: EV_Brake1ESCCONTIVN75XGP2
Coding: 517E4098256A847F8A7B027BA48821E6390000 (hex)
[No fault codes]

Instrument cluster
Part #: 7E0920970L
Component: KOMBI
Software version: 1008
ASAM/ODX identifier: EV_Kombi_UDS_VDD_RM09
Coding: 170B010100 (hex)
[No fault codes]

Airbags
Part #: 7E0959655D
Component: VW10Airbag00J
Software version: 0016
ASAM/ODX identifier: EV_AirbaVW10BPAVW12X
Coding: 00000000000000000000000000000000304A (hex)
[No fault codes]

Steering angle
Part #: 6R0959654
Component: LENKW.SENSOR
Software version: 0070
ASAM/ODX identifier: EV_LWSKLOVW25X
Coding: 01 (hex)
[No fault codes]

Parking/steering assist
Part #: 7E0919475R
Component: PARKHILFE 4K
Software version: 0210
ASAM/ODX identifier: EV_VW75XParkAssis4K
Coding: 108008 (hex)
[No fault codes]

Heater & air conditioning
Part #: 7E0907047S
Component: Climatic-T5
Software version: 0607
ASAM/ODX identifier: EV_ClimaticT5
Coding: 0000000003 (hex)
[No fault codes]

Navigation
[ECU not present]

Radio
[ECU not present]

Central electronics
Part #: 7E0937090
Component: BCM PQ25 Max4
Software version: 0736
ASAM/ODX identifier: [none]
Coding: A0A439900A61349193284F646CEB9EFC8DA0718960CC6D603204003F0800 (hex)
[No fault codes]

CAN network gateway
Part #: 7E0909901
Component: GW-K-CAN TP20
Software version: 0736
ASAM/ODX identifier: [none]
Coding: 042305 (hex)
Fault codes:
01300 Control Module for Navigation with CD-Rom (J401)

Immobilizer
Part #: 5K0953234
Component: IMMO
Software version: 1008
ASAM/ODX identifier: EV_Immo_UDS_VDD_RM09
Coding: 000000 (hex)
[No fault codes]

Battery regulator
Part #: 7E0907534
Component: Batt.regelung
Software version: 0736
ASAM/ODX identifier: [none]
Coding: 030B1A73 (hex)
[No fault codes]

Infotainment system
Part #: 1K8035150E
Component: MU-E-D-ER
Software version: 6495
ASAM/ODX identifier: EV_MUEnt4CGen2LGE
Coding: 065700003C00000041111101008000001F0000860000010001 (hex)
[No fault codes]

Obtained with Carista 610099 for iOS.
Download app: ‎Carista OBD2
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[osman]

The fault us returning randomly with no pattern whatsoever .. a restart clears it straight away for unspecified time until it randomly does it again … Carista is pretty useless as the fault clears itself so doesn’t show up

 

[Broadside]

When it happens again can you plug Carista in while the engine is running to grab the reported fault codes before they disappear on the next engine start?

 

[osman]

When it happens again can you plug Carista in while the engine is running to grab the reported fault codes before they disappear on the next engine start?

Will try that

 

[osman]

Code is 04875
A quick search comes up with a coolant pump connection but nothing specific that I can find ..
Carista just got another £10 out of me.

Just happened again and upon scrutiny it says two codes .
The first one ( under heading basic obd2) is P261A. And says coolant pump “b” control circuit open .
The second code is the previous one mentioned ( under heading engine )
04875.
Interestingly you can reset the fault code without restarting the engine using Carista and the limp mode is reset and the engine runs normally … until the next time of course !

 

[osman]

So now I have another fault with the catalytic converter icon on solid . The flashing management system went off on last restart and stayed off for a fair drive but now I have this new situation with the catalytic converter warning light on permanently .. there must be some connection … anyone out there experience something similar ? It’s in for a service on the 11th but I’ve now had to cancel a journey to Plymouth from Southampton on Friday as I don’t feel confident driving with this warning light on constantly and I’m pretty sure the limp mode hell is only waiting for me to think it’s stopped before it just starts again … what a pain in the ass.
One other strange thing is there is no error code coming up in Carista for the catalytic converter light being on

 

[osman]

After parking up for 20 mins today both warning lights have stopped again .. this is ridiculous.. now my van is preventing me from travelling due to ghost like behaviour of dashboard warning lights .. I thought Covid was enough already !
anyone else plagued with false warnings like this that miraculously fix themselves … but then leave you totally bemused as to wether to drive the thing or not . It’s a very frustrating situation as it’s so hard to plan anything

 

[mmi]

the catalytic converter icon on solid .

Do you mean this? Accumulated soot in the DPF (Diesel Particulate Filter) has reached upper limit - usually because of a lot of short journeys recently. Or some fault is preventing normal DPF regeneration.

 

[osman]

View attachment 126158
Do you mean this? Accumulated soot in the DPF (Diesel Particulate Filter) has reached upper limit - usually because of a lot of short journeys recently. Or some fault is preventing normal DPF regeneration.

Nope mine is the one far right bottom . Fault in Catalytic converter .. decrease speed drive carefully to qualified engineer the engine should be checked ! is basically what the manual tells me …and before this started I was getting regular engine management system fault warnings along with being subjected to limp mode .. as stated both have now randomly stopped but I’m sure that’s just temporary…

 

[mmi]

Nope mine is the one far right bottom . Fault in Catalytic converter ..

Ahhh.... this one then


Indeed the manual refers to catalytic converter. However, the light actually in general just indicates elevated emission level. Actual causes can be numerous. For EU5 (non-AdBlue) engine we don't have much data.

Anyways, the serious one is the flashing coil light - it's indication of actual fault in the engine.

The first one ( under heading basic obd2) is P261A. And says coolant pump “b” control circuit open .
The second code is the previous one mentioned ( under heading engine )
04875.

Actually fault 4875 = P261A thus only one fault - a coolant (electrical) pump.

 

[osman]

Yes .. the problem is it so intermittent.. today it happened only once … with a lot of miles driven yesterday about 5 times with hardly any miles .. the solid emission light has now gone off and seems to be over itself .. the flashing light I expect to see every time I don’t want to see eg just as I’m about to embark on a long journey or worse the day before a planned journey.. I’ve basically cancelled all trips until after the 11th when it’s serviced … will tell them the fault code .
The main water pump and cambelt were changed by vw only last year ! So that should be under guarantee I can only presume this is yet another coolant pump that was overlooked or rather not expected to need replacing

 

[Gilly76]

Just happened on this thread, as I have the same warning light on now too. It actually came on whilst in France on holiday, and we had to drive 780miles up the Autoroute yesterday to get home......No dip in engine performance, so we carried on. The van is still in warranty so I'll get it booked in and see what they say.

 

[osman]

Just happened on this thread, as I have the same warning light on now too. It actually came on whilst in France on holiday, and we had to drive 780miles up the Autoroute yesterday to get home......No dip in engine performance, so we carried on. The van is still in warranty so I'll get it booked in and see what they say.

Mine was a water pump (b) had it replaced cost £330 plus vat

 

[osman]

Ok my catalytic converter warning light has come on again this time it’s on constantly .. no other warning lights no flashing just this one .. no decrease in engine performance that Im aware of any ideas ? The Manual is useless

 

[osman]

Ok my catalytic converter warning light has come on again this time it’s on constantly .. no other warning lights no flashing just this one .. no decrease in engine performance that Im aware of any ideas ? The Manual is useless

Maybe I just fixed it I ran Carista and it said something about exhaust gas which I was able to reset using the app without paying for pro version and the light has gone off .. nice ! Just hoping it stays off now that will save a lot of wasted time and money no doubt at a garage .
Carista has certainly been useful for resetting these pesky lights that stay on after a temporary fault ..