Engine Management Fault

[cmc]

Hi

I was driving in to work today and without warning or notice my engine management light came on (you know the yellow one).

My car is 3 years and 2 months old (just out of warranty - dam) 20k on the clock and a Leon Cupra. I turned off the engine and restarted and it's still there. There is no notable performance loss, turbo seems to spool as normal and engine idle appears normal etc. So I don't think it is a coil pack.

Can anyone recommend any advice before a i book it into the dealer for them to hook up Vagcom? I've no idea what the fault could be, anyone any thoughts what it could be?

thanks in advance

cmc

 

[AKcupraR]

It could be the MAF? mine went last month, the egnine light came on with no warning on the motorway.. All thou you supposed to loss power I didn't really notice any..

 

[cmc]

Anyone know how much a MAF would be fitted?

Also if this is it, is it safe to drive? I'm worried about doing any damage.

cmc

 

[Revo Kev]

It's unlikely to be your MAF... these wouldn't pull up any fault codes unless they were really bad. Could be any number of things, not much you can do without knowing what the error code is... you'll then have an idea of what needs fixing/replacing/resetting!

 

[Mitchy]

Trust me you would know if your maf was on its way out!

There is a mega drop in performance.

It will be something stupid like an overtemp on 1 of the many millions of sensors planted around the car! If the car is running fine, and you have noted no loss in performance then im 99.9% sure it will be an ignore fault!

Disconnect the battery for 10mins, reconnect and the light will go out! If the light goes on immediately afterwards then get it checked properly, if not i personally would ignore it!

 

[Jonah]

If your engine is running fine it won't be the lambda sensor - I bet (although there are potentially lots of things) it is the engine coolant sensor.

 

[cordobabrendy]

my maf was dead but still went on and was barely slower than normal.

 

[traumapat]

i stand to be corrected but..

if a fault developed which is likely to damage your engine , the car would go into limp mode. all power will drop until your left with enough to limp home.

if it isnt doing that then id go with the previous advice and disconect battery to reset it. my old astra needed this every 6 wks. light came on, limp mode. pull over and reset.

the car worked fine but a lousy sensor kept telling the car somthing was amiss when it wasnt. it was traced to the maf which was 500 quid to fix! so i kept on resetting , and resetting etc..

hope its nothing

good luck mate

 

[cmc]

update

just disconnected the battery for half an hour. Reconnected it 5 mins ago and the fault seems to have cleared. Thanks for the advice everyone (always worth checking SCN before doing anything with the dealer!)

Just one question though. I thought I'd use it as an opportunity to do a throttle body alignment. So I done a search and took the advice of:

reconnect battery
Turn key to position just before ignition
Sit for 3 mins (I sat for 8)

I was expecting to hear beeping noises but couldn't hear a thing. Am I doing something wrong?

Is there anything else I need to do after reconnecting the battery or will the ECU just adapt over the nect week or so?

Cheers

cmc

 

[cordobabrendy]

tba is inaudible unless you are standing at the engine with the bonnet up, its only a small flap and reset, its not wildly opening anc closing or owt.

 

[slp530]

had the same problem on my 04 ibiza and found it was the brake light switch, apparently the engine managment light flashes if you press the brake and the switch is faulty. get some one to look at your brake lights while pressing the brake pedal.

 

[Revo Kev]

Coolant temp sensor problems would also cause a lack of performance.
Personnally if any of my cars had faults I'd rather know exactly what was up rather than resetting the ECU and ignoring it... it'll no doubt turn out to something and nothing although it's got to be worth checking.

 

[Timbo]

yep - my light came on recently and it was a dodgy engine coolant temp sensor ! - sounds quite common.

 

[danielbarnett]

my light came on in my 01 lc. booked into the dealers, it then went off a few days before. 6 months later it came back on, booked into the dealers again, the very night before (the other friday) it went off again! Taking the..

Went the dealers anyway, they said that it may not show anything in the memory now its gone off, so do i want to waste £23?? Nope! So as of now its off still, if it comes on i will hot tail it down the stealers !

 

[Revo Kev]

I'd get to a meet and have someone plug their VAGCOM in... save's you the £23 and give you a bit of piece of mind as to what the problem is/was and whether it's something that needs sorting or not. Small faults can have knock on effects and cause bigger ones, 9times out of 10 that's not the case but hey.

I'd just rather know why my car was telling me something was wrong, intermittent fault or not. Btw an intermittant fault that puts on the CEL will normally take 7 ignition cycles to clear.

 

[cmc]

I'd get to a meet and have someone plug their VAGCOM in... save's you the £23 and give you a bit of piece of mind as to what the problem is/was and whether it's something that needs sorting or not. Small faults can have knock on effects and cause bigger ones, 9times out of 10 that's not the case but hey.

I'd just rather know why my car was telling me something was wrong, intermittent fault or not. Btw an intermittant fault that puts on the CEL will normally take 7 ignition cycles to clear.

Thanks for the avice Kev (and others). I will try and get hooked up to a Vagcom as I think you're right. These don't just come on for nothing.

What is the impact of having a dodgy engine coolant sensor anyway? anything serious in the short term?

On another point. Ever since I disconnected the battery the indicators no longer flash when I lock the door and arm the alarm. It's almost as if the alarm is not arming. The LED is lit up on at the door though. Could this be related?

Cheers

cmc