What do you do when the engine management light comes on?

motorguy

Joe_Horner wrote: »

Except that, as mentioned above, some faults don't get stored. In fact some faults don't even register when the corresponding light's on.

My partner's Mondeo has a (very) intermittent ABS warning light but shows no fault - and no problems in live data - even when it lights up driving with the correct Ford software monitoring it. The ABS also operates normally while it's illuminated. Good luck diagnosing that one!

Correct as in Ford themselves? I'd be very surprised.

A lot of OBD port readers cant read ABS circuit faults

sevenhills

missile wrote: »

I would guess the fault is emission control?

The guy said it might be regenerating, but there were no other lights on.
It has been on for a day 1/2 now, if its still on tomorrow, I may take it in again. Last time it was on for 2 days, took it to the workshop and it went off before I got there, lol

macman

Regeneration of the DPF should not throw an EML fault code, as it's a standard function. Your workshop manager appears to be talking a different language, and based on the above comment about not storing fault codes, it appears to be total b*ll*cks.

Joe_Horner

motorguy wrote: »

Correct as in Ford themselves? I'd be very surprised.

A lot of OBD port readers cant read ABS circuit faults

Correct as in Forscan, which will read & monitor (and alter) everything the official software can including ABS and airbags.

As far as I can ascertain the fault is likely to be on the dash circuit board and is lighting the light without any signal from the ABS to do so. There are a few "known faults" on that board giving spurious gauge readings & so on.

The fact that the ABS still works properly when the light is on backs that up seeing as it should shut down in the event of an active fault.

missile

sevenhills wrote: »

The guy said it might be regenerating, but there were no other lights on.
It has been on for a day 1/2 now, if its still on tomorrow, I may take it in again. Last time it was on for 2 days, took it to the workshop and it went off before I got there, lol

If the DPF is blocked or EGR valve needs cleaning this will show the engine warning light fault.


Don't ignore warning light :eek:

Any VAG garage will charge £60 to properly investigate and diagnose the fault.

sevenhills

missile wrote: »

Don't ignore warning light :eek:

Any VAG garage will charge £60 to properly investigate and diagnose the fault.

I took it into our workshop today. They kept it, and will be sending it to VW.
Speaking to another driver, they also kept his Crafter after the third visit. This time they said that because the EML was on, it could go into limp mode at any time.

motorguy

sevenhills wrote: »

I took it into our workshop today. They kept it, and will be sending it to VW.
Speaking to another driver, they also kept his Crafter after the third visit. This time they said that because the EML was on, it could go into limp mode at any time.

As an aside, this is the way "repairs" are going - you return the vehicle to the dealer, he reads the ECUs and sends the data set to the manufacturer who then advises on what action to take.

I've had this happen twice with VW now on two different cars.

What chance does a private mechanic have these days?