Getting code 284 - ECM135F

[Seesure]

Hello gentle folk, I'm new on here and relatively new to Volvo's.

Back in June picked up an old (05 plate V70 D5, manual box) as a shed to haul crap around in.

It's been great, approx 195k on the clock and goes like the proverbial Sh*t off a shovel.

A few weeks back I noticed that the turbo wasn't working and it was way down on power, having to drop to 3rd or 2nd gear in some instances to get up hill.

It's not in limp mode as the revs still get up to 4k ish but there is no oomph as there's no turbo kicking in, no smoke coming from the exhaust.

BUT it's only like this after about 20-25 minutes of driving from cold... up till then it's normal and then you can feel a change to the engine almost as though it's had a little hiccup.

I took it to an independant specialist who read the codes as "engine system service required" comes up in the dash. The only code is "284: ECM-135F Mass Air Flow (MAF) sensor. Signal too high."

They changed the intercooler and smoke tested the intake system, no leaks seen and the problem still persisted.

They then changed the MAF to known good one and problem was still occuring. They checked the EGR value and that was good.

Does anyone have any ideas as to where else can we look ?

The car is great otherwise and I actually enjoy wafting around in it ...

Cheers SS

[davebb]

Hi is the car a 185 or 163 bhp ?
If MAF reading is to high it will not be a Boost leak,
i would say to test and see what the boost pressure goes up to with your foot down in 3rd gear, you can use a obd2 unit for this as long as the car has not been remapped, if it has been remapped it will go up to about 21psi if not it should be around 16-17psi max boost,
Dave

[Seesure]

Thanks davebb, it's the 185 version, once the fault kicks in nothing happens when you push your foot right down in pretty much any gear.

The revs increase but the increase in speed is glacial - the Indy believes the car has been mapped at some point and this may be masking the true fault code. Before the fault manifests itself the car really is quick and responds really well, especially in 3rd and 4th gears.

I'm going to try and book it in with a mapping specialist to see if they can spot anything obvious or wind it back to a standard map to see what is happening.

Although it's an old car it is too good to give up on yet...

I'll update what happens once I've had chance to get the mapping looked at.

(It might take a while though as I have a silly little SLK that has developed oil in the engine wiring loom !!! So that needs sorting for the other half... )

[davebb]

Hi
What makes hi think it has been remapped ?
i think the 185bhp has higher boost pressure,

Dave

[vickyg]

Following this post as I am also suffering ECM-135F (signal too low) on my 185. I'm thinking it's an air leak as just had major engine work.

[Seesure]

Originally Posted by davebb

Hi
What makes hi think it has been remapped ?
i think the 185bhp has higher boost pressure,

Dave

Hi Dave,

The Indy I took it to spotted that it was mapped when he took it out, it was "very" quick when the turbo kicked in.

In gears 2 through to 5, it was easy to spin the wheels in 3rd at 50mph..

(also my other car is a 2003 M5 and would probably give it a run for its money from 40-80mph)

Plus he was getting a "check sum" error when looking for stored codes.

What I did was to take it a re-mapping workshop and they've installed the standard V70 map, I drove it home last night, about 22 miles in mixed traffic.

The fault seems to have disappeared as going up hill was no longer a drop down to 2nd gear.

All I need to do is get rid of the "service engine management system" message from the dash...

[Seesure]

Originally Posted by vickyg

Following this post as I am also suffering ECM-135F (signal too low) on my 185. I'm thinking it's an air leak as just had major engine work.

We did a smoke test for an air leak and that came back clear, we changed the MAF over for a known good one and it still persisted.

Having taken the car back to a standard Volvo map it seems to be fine now.