17705 fault code at idle

DannyC87

Rubbing is Racing :-)
Mar 4, 2008
3,459
0
Hello,

I am getting this fault code consistently and its bringing on limp mode :(

The code does not reappear if it is cleared whilst on throttle and kept accelerating; however on deceleration, when nearly at idle the fault code reappears. When sitting at idle, a little blip (only a couple of hundred rpm) will bring on the fault code as the revs settle again.

I have checked the DV which appears to be functioning properly.
I have a catch can installed so no PCV system and very few under-intake manifold vac pipes to check, although the ones that are there have been checked.
All the hoses around the N75 have been checked.
A different N75 has been tried.
All main boost hoses to/from intercoolers have been checked.
The throttle body gasket has been replaced.

When running with the MAF unplugged the fault code does not appear.
When running with the MAP unplugged the fault code does not appear (although a load of others do!)

The car IS making requested boost, and flowing over 220g/s on a stage 1 map boosting 22psi max.

My suspicion is that the MAF reading it too high and the MAF is goosed!

Does anyone have any other suggestions as to what the cause may be?

Cheers
 

rsmith

Robbie
Apr 28, 2004
2,797
1
Tipperary, Ireland
Its a long shot but, i used to get this error and limp mode from the IAT(intake air temp) from a recent remap, it turns out there was not actual leak more over a problem with my map, its a long shot but it looks like you have all the basses covered.

MAF reading is way to high, 220g/s(we wish), did try trying cleaning it
 

DannyC87

Rubbing is Racing :-)
Mar 4, 2008
3,459
0
Its a long shot but, i used to get this error and limp mode from the IAT(intake air temp) from a recent remap, it turns out there was not actual leak more over a problem with my map, its a long shot but it looks like you have all the basses covered.

MAF reading is way to high, 220g/s(we wish), did try trying cleaning it

Logged my IAT's yesterday and they seemed okay; constant around 12-15* (WMI). Will be trying a new MAF later today.

Cheers
 

Jamesrowe

Active Member
Feb 6, 2009
51
0
Dorset
I had this code come up along with another one, 17695 - which was an open curcuit to the n249 valve. I done the n249 bypass and cleared the codes and they haven't come back since, that was over two weeks ago now!
 

DannyC87

Rubbing is Racing :-)
Mar 4, 2008
3,459
0
new MAF has not fixed this. I bypassed the n249 years ago.

going to weld up a bung with a tyre valve in it later to pressure test the system.

Could the fact this is only happening at idle relate it to my recent TB issues?
 

PSX

Active Member
Sep 20, 2009
271
1
Wondering if I can possibly contribute.. I am getting this code, in addition to 16885 (vehicle speed sensor - implausible signal) and 16891 (idle RPM higher than expected). Recently I've been suspecting that my MAF may be failing and causing slightly less than smooth running under certain circumstances.

Already tried an Ebay MAF which killed all my boost after 20 miles of driving so now back on the Bosch. Also swapped my vehicle speed sensor (sits on top of the gearbox) - but the fault returned a week later. Currently I've cleared the faults again and they only reoccur every 7-10 days. I have not yet inspected any of the intake hoses or performed throttle body clean/reset.. Was it an original Bosch MAF that you replaced with?

Cheers,

Alex
 

DannyC87

Rubbing is Racing :-)
Mar 4, 2008
3,459
0
Replaced with original Bosch MAF yes.

Today I have:
Pressure tested the system from the top inter cooler hose just after the charge pipe up to 25psi - no leaks.
Removed and refitted the TIP to ensure tight connections
Removed and refitted charge pipe and silicon elbow from turbo to charge pipe to ensure good connections
Realigned my throttle body
Removed and cleaned with electrical contact cleaner IAT sensor and MAP sensor

Going to pick up a 2nd hand TB to try next.
 

DannyC87

Rubbing is Racing :-)
Mar 4, 2008
3,459
0
Success I think!
Following my earlier activities, I reset the TB using VAGCOM rather than just my race-diagnostics gauge, and changed my idle speed back to standard (it had been increased 900rpm to avoid vibrations from dog-bone mount). Just driven 80miles and NO limp mode!!
Something must have worked but I'm not sure what!
 

rsmith

Robbie
Apr 28, 2004
2,797
1
Tipperary, Ireland
Success I think!
Following my earlier activities, I reset the TB using VAGCOM rather than just my race-diagnostics gauge, and changed my idle speed back to standard (it had been increased 900rpm to avoid vibrations from dog-bone mount). Just driven 80miles and NO limp mode!!
Something must have worked but I'm not sure what!

Fingers crossed Danny.Are you getting vibration now with the idle lowered and the DBM, it must be well settled in by now?
 

DannyC87

Rubbing is Racing :-)
Mar 4, 2008
3,459
0
Fingers crossed Danny.Are you getting vibration now with the idle lowered and the DBM, it must be well settled in by now?

No, as you say, must be settled in by now..30k miles later!! On the plus side I am still flowing just over 220g/s with a new MAF :D
 

rsmith

Robbie
Apr 28, 2004
2,797
1
Tipperary, Ireland
+ the effects of 7.5* timing.. really need to sort out a rolling road session!

WMI must be really helping you out, i put an extra 1.5 degress today and started throwing CF's with no obvious gain in power.Starting to think now my FMIC pants.

An RR would be interesting, but personally i take them with a pince of salt.
 

DannyC87

Rubbing is Racing :-)
Mar 4, 2008
3,459
0
WMI must be really helping you out, i put an extra 1.5 degress today and started throwing CF's with no obvious gain in power.Starting to think now my FMIC pants.

An RR would be interesting, but personally i take them with a pince of salt.

Its all the dyno lottery! As soon as it starts throwing CFs you lose any potential gains and more sometimes. I get a couple of CFs toward the red line, but other than that, zero's across the board :D
 

DannyC87

Rubbing is Racing :-)
Mar 4, 2008
3,459
0
AEM kit imported from the USA although I believe they are available in Europe now. Progressive controller has everything built in - pressure sensor, error control output etc.
 

rsmith

Robbie
Apr 28, 2004
2,797
1
Tipperary, Ireland
AEM kit imported from the USA although I believe they are available in Europe now. Progressive controller has everything built in - pressure sensor, error control output etc.

Just reading about the AEM WMI, its a seriuos bit of kit Danny, would you say its worth the money, because it ain't exactly check.
 

DannyC87

Rubbing is Racing :-)
Mar 4, 2008
3,459
0
Just reading about the AEM WMI, its a seriuos bit of kit Danny, would you say its worth the money, because it ain't exactly check.

If you have the time to put into setting it all up correctly yes. With lower EGT's, IATs and cylinder temperatures there is much less ECU pull toward the top end. Much freer revving all through the rev range & smoother power delivery. Timing advance can yield significant power increases (IIRC DJP's car sees roughly 10bhp from 3* of timing).

It can be a PITA though - for my Germany trip I had to take 20ltrs of mixed methanol in the boot! Always carry spare methanol with me. It is cheap tho, £12 for 20ltrs on ebay. Under normal conditions I use 2.5ltrs of mix over ~300miles. At the 'ring I used 2.5ltrs in 2 laps (26miles)
 
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