ECM-6805 - Overboost?

nebletic · Post by **nebletic** » 09 Jun 2024, 04:27

Hi there

I recently bought a used Volvo S60 2.4T FWD and serviced it yesterday.

About 3 days after installing a 3inch BSR Downpipe (not sure if it has anything to do with it) I am getting a CEL (not only for O2, getting it fixed with a tune..) but also for this:

ECM-6805 control system boost pressure fault - Pressure too High

After searching endlessly I couldnt find anyone with the same exact Code, most of them have Faulty Flow or something else.

I notice the following:

No Limp Mode
Maybe reduced power at high speeds? Couldnt reach more than 220 Kph, but maybe its limited.. not so important..
Slightly reduced power at some times, maybe just placebo..

I went for a drive with the Vida Graph open and found the following in the Graph.

Thanks for any help

Post by **jonesg** » 09 Jun 2024, 10:34

i'd test the wastegate function,
make sure theres a slight preload on the actuator rod, should't rattle around..

Post by **jonesg** » 10 Jun 2024, 09:40

maybe clean the turbo control sensor too.

yanga001 · Post by **yanga001** » 13 Jun 2024, 09:15

I’ve seen overboost on Acura based td04 setups. Usually it was a jammed actuators or stuck blowoff/bypass valve.

In those cars it would cause the car to surge forward and slow down and it could not go over 40kph.

nebletic · Post by **nebletic** » 13 Jun 2024, 10:05

jonesg wrote: ↑10 Jun 2024, 09:40 maybe clean the turbo control sensor too.

Hi there, I've just done that. I'll report back if that made a difference. Thank you!

nebletic · Post by **nebletic** » 13 Jun 2024, 10:06

jonesg wrote: ↑09 Jun 2024, 10:34 i'd test the wastegate function,
make sure theres a slight preload on the actuator rod, should't rattle around..

Hey, yeah there's no rattle, it seems all fine to me. Maybe readjusting it would help?

Post by **jonesg** » 13 Jun 2024, 18:06

i have a turbo gauge on top of the dash glued to the A pillar, i can see the boost kick in.
it shows vacuum when driving normal.
it tells me a lot at a glance.
you might need to clean the turbo boost control valve in the air pipe near the turbo, it gets oil gunked.

Post by **matthew1** » 13 Jun 2024, 18:22

^ A numbered boost gauge should be a federal requirement for anyone with a non-stock turbo car... it's 100% indisputably indispensable.

nebletic · Post by **nebletic** » 14 Jun 2024, 00:41

jonesg wrote: ↑13 Jun 2024, 18:06 i have a turbo gauge on top of the dash glued to the A pillar, i can see the boost kick in.
it shows vacuum when driving normal.
it tells me a lot at a glance.
you might need to clean the turbo boost control valve in the air pipe near the turbo, it gets oil gunked.

Hi there, yeah, I have done that as previously mentioned. I'll be going on a longer drive today, after that I'll check if the error came up again or not.

matthew1 wrote: ↑13 Jun 2024, 18:22 ^ A numbered boost gauge should be a federal requirement for anyone with a non-stock turbo car... it's 100% indisputably indispensable.

Yeah, whenever I upgrade from these stock ones I'll add that for sure.

nebletic · Post by **nebletic** » 14 Jun 2024, 09:10

Hello everyone, sadly cleaning the TCV didn't fix the problem. It registered another case of overboost about 200km ago. Is there anything else that could be the issue?