Rob
So my C70 is being temperamental.
I took it for a drive and noticed it was producing more boost than expected (around 28psi) but had a stutter and was making no power. Engine light came on.
Idled it home and extracted codes:
EFI-445 Pulsed secondary air injection system pump signal
EFI-444 Accelerometer signal
EFI-621 Fuel tank pressure sensor signal
EFI-616 EVAP canister shut off valve signal
EFI-447 Pulsed sec air Injection system solenoid valve signal
EFI-554 Misfire with catalytic converter damage cylinder 4
EFI-545 Misfire with TWC damage from at least one cylinder
EFI-422 Atmospheric pressure sensor signal
Went digging and found an intercooler hose had partially blown off, refitted and secured it, cleared codes, then took it for another drive.
Drove OK but the boost pressure was still too high. Engine light came back on.
Idled it home and extracted codes:
EFI-445 Pulsed secondary air injection system pump signal
EFI-444 Accelerometer signal
EFI-621 Fuel tank pressure sensor signal
EFI-616 EVAP canister shut off valve signal
EFI-447 Pulsed sec air Injection system solenoid valve signal
EFI-233 Adaptive idle air trim
Found nothing wrong, cleared codes and took it for a gentle drive to prevent excessive boost, drive beautifully but the engine light came on again.
This time i got:
EFI-445 Pulsed secondary air injection system pump signal
EFI-444 Accelerometer signal
EFI-621 Fuel tank pressure sensor signal
EFI-616 EVAP canister shut off valve signal
EFI-447 Pulsed sec air Injection system solenoid valve signal
EFI-355 Mass air flow (MAF) sensor, faulty signal
Once again found nothing obvious wrong, clear codes and took it for another gentle drive, drove beautifully and no engine light came on, I drove it for over an hour. After this I gave it a little more throttle in order to get the boost up again, it instantly hit 28psi and the engine light came on.
This time I got
EFI-445 Pulsed secondary air injection system pump signal
EFI-444 Accelerometer signal
EFI-621 Fuel tank pressure sensor signal
EFI-616 EVAP canister shut off valve signal
EFI-447 Pulsed sec air Injection system solenoid valve signal
EFI-554 Misfire with catalytic converter damage cylinder 4
EFI-545 Misfire with TWC damage from at least one cylinder
My understanding is that EFI-445, and EFI-447 are irrelevant in Australia
Mathews Volvo site suggests that misfire codes could be a direct result of EFI-444 Accelerometer signal
I would suggest that the EFI-422 Atmospheric pressure sensor signal fault was caused by the massive boost leak that was a result of the hose being off so I am not worried about that one.
Looking at what is left I get:
EFI-621 Fuel tank pressure sensor signal - could be low fuel tank pressure, not sure how relevant this is.
EFI-233 Adaptive idle air trim - could be a faulty IAC but i fail to see how this is related.
EFI-616 EVAP canister shut off valve signal - not sure if this is relevant.
EFI-444 Accelerometer signal
EFI-355 Mass air flow (MAF) sensor, faulty signal
Seeing as EFI-355 has only appeared once and EFI-444 has appeared many times I would think maybe this is where I need to start, Matthews Volvo site suggests the Accelerometer is the Throttle position sensor.
In saying that I still don't know what is causing the high boost in the first place. I wonder if it is the cause or a consequence.
Any opinions?
brock
Do you have an ARD tune in it (I think I recall that from your C70 thread but it's been a while since I looked)? I get the accelerometer and the fuel tank pressure codes on my tune which I do not get on the standard tune. My understanding is on some models there is an accelerometer, I think on the engine subframe, which detects excess vibration that may trigger the knock sensors, we do not have this in Australia (at least I can't find it on mine!).
Rob
OK. Yes, I do have an ARD tune.
I seem to recall seeing it and the fuel tank pressure codes a long time ago but wasn't certain.
I might start with a basic leak hunt and check the wastegate adjustment before I dig too deep.
Philia_Bear
Sure the vac line is connected to the wg etc
The only way to get high boost level is something failed in the wg vac line system or failed selenoid or map (i forget if 4.4 has this)
Rob
It all looks to be in place. I will investigate properly tomorrow. I replaced the TCV some time back but have never really given it a good bootful since then.
850AWD
Was it the TCV, wastegate?
Rob
Ooh. This was a long time ago. It was a giant vacuum leak at the IAC valve
850AWD
How do you think vac leak allowed over boost? Response to wastegate pressure?