Flashing coil light without MIL - no diagnosis required

[John A]

I am curious as to what circumstances the flashing coil light and limp mode occurs without the check engine light coming on.
I haven't plugged the van in yet, but it's happened once before ages ago and I think it was boost pressure regulation and, in the short term, is resolved by cycling the ignition.

I am just curious to know if there are levels of seriousness that will put a van into limp mode, but won't activate the EML

 

[whodat]

Yes - definitely.

For instance on an older vehicle I changed my windscreen washer jets and the van kept going into limp mode.
Turns out I hadn't used the 'heated' version. Managed to fix it but - yes, there are some non-serious problems that will make limp mode.

 

[John A]

That's crackers that the wrong washer jet would put a van into limp mode
I think this is a boost pressure regulation issue and I wonder if it's anything to do with the MAP not being up to the job of the software.
It's only happened twice and I've seen some modified cars and vans using the MAP sensor from a 3.0 Amarok

 

[mmi]

The "yellow submarine" light indicates emission related issue - engine still runs just fine. Usually takes quite a few running cycles to get confirmed before light turns on. Can be seen well beforehand by peeking at OBD2 pending faults registry.

Flashing coil light indicates serious/immediate engine problem - usually also the limp mode. Indeed cycling ignition resolves it - till ECU self-diagnosis detects the fault again.

 

[John A]

I didn't know the EML was an emission related issue. In previous vehicles (VAG) this would illuminate to draw your attention to issues around running, as well as (on one occasion) the ABS system.

I've detected this fault once before - months and months ago now, under similar circumstances where the van was being driven quite hard to accelerate to motorway speed.