171 fault code :(

[c70mel]

Driving down the road today in my C70 1999 2.4 (non turbo) and the 'Engine management system malfunction' light came on... ARGHGHHGHG

Took it to a local volvo specialist who very kindly hooked it up to this hand held box of tricks and found the error code '171'. However he hasn't got the fault code list yet so im non the wiser what the problem is.

He reset the fault codes and the light went off.. drove a few miles light stayed off... phew.. on my way home and it comes back on again ARGHGHGHG


Anyone any idea what this 171 fault code means? I'm going to ring the garage who i bought it from tomorrow just trying to do some research into it first.

Cheers!!

[andi t5]

try this http://www.troublecodes.net/OBD2/ 171 is fuel trim lean,vacuum leak?

[Aiken]

P0171 is Adaptive Over Time according to my Volvo info for a 1999 C70, although since you've got the non turbo not sure, cause this uses a DENSO system rather than the ME7 (apparantely). I guess since the DTC are a standard, at least Volvo standard (which I read is different to the other standard) the codes should be consistent.

Absolutely no idea what the heck this means though :slap:

[volvotuning]

Basically, and adaptive fuel trim error occurs when the ECU cannot compensate on the fuel trim any further due to a fault.

In laymans terms...

Normally, to cater for slight variations in engines, minor component tolerance, and various other dynamic conditions, the ECU adapts the fuel trim so that it's always fueling according to a preset value. The adaption process allows for a "window" of tolerance in which it can operate so that such adjustments can be made. If these adjustments reach a limit, then it means that something is wrong because the ECU is having to over-compensate more than it should. It therefore flags up a fault saying, "Hey something is wrong because I can't adjust the fuel trim any more."

Then it's up to the diagnostics expert to figure out why!

It is often caused by an air leak, but can be a sensor fault that hasn't been detected.

Adam.

[Andrew]

try this http://www.troublecodes.net/OBD2/ 171 is fuel trim lean,vacuum leak?

I had this on mine last week. Slight airleak on an elbow just to the front left of the engine underneath the fuel gauge. You could tell as if you had the motor running and moved the elbow joint with your fingers you could hear the leak.

Took my local independent 10 minutes to fix and at no charge to me :)

[c70mel]

Cheers guys excellent help and info!!!

Cheers for the layman terms as well as the other bit just confused me hehe. Sounds alright then and nothing to major to worry about (hopefully)

I have already took the car back once to the garage (still in its 3month warranty) due to it being hard to get into reverse occasionally. While they had it in they cleaned out the throttle body (i think thats what they called it) as the revs were dropping abit too much when coming to a stop. Its a manual btw. This clean out has seemed to of fixed the revs problem.

You think this clean out may of caused any problems?

Cheers again!! :)

[Wobbly Dave]

Sounds most likely to be the well known rubber elbow joint issue (left hand end of the inlet manifold nr the tstat housing).

[volvotuning]

Although not a major issue engine wise, running with a fueling problem for too long will eventually result in premature catalytic converter failure, which is an expensive item. So the sooner you get this sorted, the better.

Adam.

[c70mel]

Although not a major issue engine wise, running with a fueling problem for too long will eventually result in premature catalytic converter failure, which is an expensive item. So the sooner you get this sorted, the better.

Adam.

True.. although the nearest time I can get it booked in is next week and i have to do alot of driving in the mean time :(

I have started the car a few times and it has smelt quite strongly of petrol so it has been running too rich when cold sometimes. Hopefully this isnt' goin to cause any more problems either or is part of this fault code.

thanks again