Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: birdman on 09 October 2011, 20:19:58

Title: fuel trim code
Post by: birdman on 09 October 2011, 20:19:58
I have been getting fault code p0170 fuel trim for a while now with local driving which self clears after a while,it illuminates the emission light,just been on holiday and done 500 miles,mainly motorway cruising,the fault didnt appear once!!car runs like a dream, went to shop just now and code has reappeared illuminating the dreaded light! anyone got any ideas,i have replaced,cleaned,inspected,everything possible associated with this code! i am a mechanic and know vauxhalls inside out but cant put my finger on this one!! any help appreciated. ::)
Title: Re: fuel trim code
Post by: TheBoy on 09 October 2011, 20:35:00
What is live data on B1S1 doing?
Title: Re: fuel trim code
Post by: birdman on 09 October 2011, 20:41:39
I will check and get back to you,thanks :y
Title: Re: fuel trim code
Post by: ndmv6 on 09 October 2011, 22:11:21
hmm,had this on mine and its a bugger to cure,i changed.....
cam sensor
maf
spark plugs
then eventually ended up replacing exhaust manifold,as it had warped..
then once that was cured,i got code p0420 due to running round with the emmissions light on,and the engine running rich,so then that was a new cat job...
Title: Re: fuel trim code
Post by: birdman on 10 October 2011, 11:51:10
The live readings on idle are:

FUELSYS1 OL_FAULT
LOAD_PCT(%) 13.3
ETC(C) 87
SHRTFT(%) 0.0
LONGFT(%) 10.2
RPM 758
VVS 0
SPARKADV 8
IAT (C) 39
MAF(G/S) 2.09
TP(%)1.6
02B1S1 (V) 0.095
SHRTFTB1S1(%) 0.0
02B1S2 (V) 0.230

Is there anything reading wrong? ::)
Title: Re: fuel trim code
Post by: feeutfo on 10 October 2011, 11:55:24
hmm,had this on mine and its a bugger to cure,i changed.....
cam sensor
maf
spark plugs
then eventually ended up replacing exhaust manifold,as it had warped..
then once that was cured,i got code p0420 due to running round with the emmissions light on,and the engine running rich,so then that was a new cat job...
0420 is pre cat, and makes little odds other than eml. It may have sorted itself with help from an Italian tune up.
Title: Re: fuel trim code
Post by: feeutfo on 10 October 2011, 11:56:57
Birdman, was lambda1 cycling once engine warm?
Title: Re: fuel trim code
Post by: birdman on 10 October 2011, 12:14:24
no it wasnt,is that the problem?
Title: Re: fuel trim code
Post by: birdman on 11 October 2011, 19:10:20
The live readings on idle are:

FUELSYS1 OL_FAULT
LOAD_PCT(%) 13.3
ETC(C) 87
SHRTFT(%) 0.0
LONGFT(%) 10.2
RPM 758
VVS 0
SPARKADV 8
IAT (C) 39
MAF(G/S) 2.09
TP(%)1.6
02B1S1 (V) 0.095
SHRTFTB1S1(%) 0.0
02B1S2 (V) 0.230

Is there anything reading wrong? ::)
does anyone know if any of these readings are incorrect? i dont understand why the emmission light keeps illuminating with a fuel trim fault,everything has been replaced,gen vaux too!!!!!!!!!!
Title: Re: fuel trim code
Post by: TheBoy on 11 October 2011, 19:19:47
The live readings on idle are:

FUELSYS1 OL_FAULT
LOAD_PCT(%) 13.3
ETC(C) 87
SHRTFT(%) 0.0
LONGFT(%) 10.2
RPM 758
VVS 0
SPARKADV 8
IAT (C) 39
MAF(G/S) 2.09
TP(%)1.6
02B1S1 (V) 0.095
SHRTFTB1S1(%) 0.0
02B1S2 (V) 0.230

Is there anything reading wrong? ::)
does anyone know if any of these readings are incorrect? i dont understand why the emmission light keeps illuminating with a fuel trim fault,everything has been replaced,gen vaux too!!!!!!!!!!
Static live data is not that helpful - you need to monitor what things are doing.

When it goes closed loop, B1S1 should cycle about once every couple of seconds, B1S2 should remain permenently lean.
Title: Re: fuel trim code
Post by: TheBoy on 11 October 2011, 19:20:50
The live readings on idle are:

FUELSYS1 OL_FAULT
LOAD_PCT(%) 13.3
ETC(C) 87
SHRTFT(%) 0.0
LONGFT(%) 10.2
RPM 758
VVS 0
SPARKADV 8
IAT (C) 39
MAF(G/S) 2.09
TP(%)1.6
02B1S1 (V) 0.095
SHRTFTB1S1(%) 0.0
02B1S2 (V) 0.230

Is there anything reading wrong? ::)
Thats why light is on.
Title: Re: fuel trim code
Post by: birdman on 11 October 2011, 19:53:42
so if the b1s1 doesnt cycle is that an o2 sensor fault? it seems to stay OL_fault  when i monitored it for 5mins engine fully warm, is it this sensor causing me grief! :'(
Title: Re: fuel trim code
Post by: TheBoy on 11 October 2011, 22:18:54
so if the b1s1 doesnt cycle is that an o2 sensor fault? it seems to stay OL_fault  when i monitored it for 5mins engine fully warm, is it this sensor causing me grief! :'(
No, not necessarily. Could be wiring, could be it is genuinely rich/lean. Could be the heater isn't working...
Title: Re: fuel trim code
Post by: birdman on 23 October 2011, 19:36:59
went for a drive today and done a live test with my maxiscan,during the 15minute drive fuel system1 showed OL-Fault and never changed,i believe this should this be switching OL to CL every couple of seconds? o2b1 was only showing around 0.015v this didnt change much on the test,i believe this is showing lean,hence the fuel trim dtc? is this likely to be a slugish o2 sensor or am i barking up the wrong tree? i have recorded the session so if any other info is required i have it! apologies for all the questions but desperate to get to the bottom of this one!!   :'(
Title: Re: fuel trim code
Post by: TheBoy on 23 October 2011, 19:45:36
went for a drive today and done a live test with my maxiscan,during the 15minute drive fuel system1 showed OL-Fault and never changed,i believe this should this be switching OL to CL every couple of seconds? o2b1 was only showing around 0.015v this didnt change much on the test,i believe this is showing lean,hence the fuel trim dtc? is this likely to be a slugish o2 sensor or am i barking up the wrong tree? i have recorded the session so if any other info is required i have it! apologies for all the questions but desperate to get to the bottom of this one!!   :'(
Not familiar with your scanner BUT:

Car should start Open Loop, and go Closed Loop when it starts to heat up.
B1S1 should, when Closed Loop, flick regularly between Rich and Lean (about once every 2s)
B1S2 should always read lean
Title: Re: fuel trim code
Post by: birdman on 23 October 2011, 19:55:12
It never went closed loop,and B1S1 cycled around 5times in 15minute test,B1S2 was constantly reading around 0.075v,do you think its the o2 sensor,it was only replaced 2years ago (genuine)
Title: Re: fuel trim code
Post by: TheBoy on 24 October 2011, 17:57:52
It never went closed loop,and B1S1 cycled around 5times in 15minute test,B1S2 was constantly reading around 0.075v,do you think its the o2 sensor,it was only replaced 2years ago (genuine)
What is CTS reading?

Was B1S1 staying mainly rich or mainly lean (although, I think irrelevant if not going closed loop)
Title: Re: fuel trim code
Post by: birdman on 24 October 2011, 18:39:39
It never went closed loop,and B1S1 cycled around 5times in 15minute test,B1S2 was constantly reading around 0.075v,do you think its the o2 sensor,it was only replaced 2years ago (genuine)
What is CTS reading?

Was B1S1 staying mainly rich or mainly lean (although, I think irrelevant if not going closed loop)
It stays lean when open loop,it doesnt seem to be switching as it should,can you explain what CTS is?
Title: Re: fuel trim code
Post by: TheBoy on 24 October 2011, 18:57:23
CCoolant Temp Sensor
Title: Re: fuel trim code
Post by: birdman on 24 October 2011, 19:07:54
CCoolant Temp Sensor
Oh, ETC on mine! :D reading 87C
Title: Re: fuel trim code
Post by: TheBoy on 24 October 2011, 19:37:22
Not sure why not going Closed Loop then,  this is where we need a lamda junkie...   ...Kevin Wood :P
Title: Re: fuel trim code
Post by: birdman on 24 October 2011, 21:06:49
Not sure why not going Closed Loop then,  this is where we need a lamda junkie...   ...Kevin Wood :P
Its weird,if let to idle the sensor will switch ol/cl every couple of seconds but when you go out for a test flight it goes to openloop-fault where it stays!?then the mixture reads lean 0.2v from s1b1,hence the rich fuel trim code coming up! Is Kevin Wood out there! ;D
Title: Re: fuel trim code
Post by: TheBoy on 24 October 2011, 21:23:28
Not sure why not going Closed Loop then,  this is where we need a lamda junkie...   ...Kevin Wood :P
Its weird,if let to idle the sensor will switch ol/cl every couple of seconds but when you go out for a test flight it goes to openloop-fault where it stays!?then the mixture reads lean 0.2v from s1b1,hence the rich fuel trim code coming up! Is Kevin Wood out there! ;D
Eh? The sensor doesn't go Open or Close loop. Thats a processing decision from the ECU
Title: Re: fuel trim code
Post by: birdman on 24 October 2011, 21:28:49
Not sure why not going Closed Loop then,  this is where we need a lamda junkie...   ...Kevin Wood :P
Its weird,if let to idle the sensor will switch ol/cl every couple of seconds but when you go out for a test flight it goes to openloop-fault where it stays!?then the mixture reads lean 0.2v from s1b1,hence the rich fuel trim code coming up! Is Kevin Wood out there! ;D
Eh? The sensor doesn't go Open or Close loop. Thats a processing decision from the ECU
The plot thickens,wish I was Eienstein! :-\
Title: Re: fuel trim code
Post by: birdman on 27 October 2011, 17:12:53
Right,just changed oxygen sensor 1 for brand new gen vaux,same problem so not that  :'(  could a dicky crank sensor cause this prob? its the only thing that hasnt been changed!!! ;D