My 96' showed the check engine (Lambda) light this evening when I stopped at the parts source to order the new timing belt because it is over due for replacement. I connected my OBD diagnostic tool and it says that there are no fault codes registered. I burrowed the hand held code reader from part-source and itreads the same.
Wonder if the OBD-II in these cars is different from the OBD-II in 95 ones and other brand of cars because my other car which is 94 volvo 850(has OBD-II port under coin holder) works perfect with my device and I have cleared the engine and tranny codes on that one many times in the past.
Also please tell if I have to read the codes with ignition ON or OFF or engine running?

 

I always read the codes with the engine running.

The scanner should work with it if it works on the 94.

 

I wonder if your OBD-II port is bad (broken/pulled out wire)

 

Thanks, I will check the port and connections/wires as soon as I finish work today.

 

I removed the port out and all wires look intact and undamaged. Tried 2 more code readers and all say "No fault codes stored". So, I disconnected the battery for about 10 minutes and reconnected and the light was gone. I took her for a little test drive and NO PROBLEMS but about an hour later I went for groccery shopping and whilecomming back home the light turned ON again.

 

I can only guess that a failing O2 sensor is triggering CEL, but there is no telling unless you can retrieve codes. Certain transmission faults also trigger CEL. Actron CP9175 scanner can access both the engine & tranny ECUs.

With the ignition OFF, connect the scanner and then turn the ignition to ON position. Follow the instruction for the scanner (which I am sure you have already done but give it another try just for the heck of it)...

Sorry I could not help you better.


JPN

 

Its all good JPN.
Iappreciate your help and understand the limits sometimes. I will try to get the reader that you mentioned and see how it goes but that also rings a bell to check the tranny fluid level just incase. I will keep you posted on any progress. I am planning to do the timing belt on monday and will try to do some more troubleshooting then. Is Gates a good name for t-belt? or should I insist for Contitech?

 

Thank you for your understanding.

No, forget Gates. Anything that bears the name Gates is a bad sign, including that screwy OS company in Redmond, WA[8D]. (No offense to other people with the name Gates, however)

I would not use anything other than Contitech; the OEM.


JPN

 

Thanks for suggestion...I am going to return it right now...and ask for Contitech.

Back to original problem, I am able to reset the light second time as well by removing the battery cable for few minutes and it has not popped in yet but I noticed a big change in gas consumpton. Its acting like a gas guzzler. Will that strengthen your belief of my O2 sensor going bad?

 

Just to update that the freaky Lambda light is ON again. Part-source said that according to their information, this car should have 2 O2 sensors whare as I dont remember seeing the second one.
Any sugestions? or do I have to pay to get the car scanned by volvo tool to get more info?

 

The turbo models do havetwo O2 sensors; one before the cat and the other aft.

At this point, you may have to bite the bullet and have a visit to the dealer. Ibelieve their Volvo tester would reveal something that the other OBD-II scanners have missed.

Many things can affect gas mileage, but in your case the O2 sensors may be playing a part in it. When was the last good tune up? If not done for over 3 years/30,000 miles, I would give it a good tune up.

See my 2nd reply at:
https://volvoforums.com/m_48928/tm.htm


JPN

 

Thanks JPN,

The last tune-up was done in this past summer andI have thrown less then 20K kms on it. The drive and running is quite smooth (No missing or rough idling).
Anyhow,I managed to pull a O2 sensor from the wrecker yesterday and put it in my car. I cleared the light by disconnecting battery and have driven it for about 90Kms (city and highway) and the light have not showed up again. The drive also feels to be more powerful and tranny shifts even better. So, hoping that my problem is gone for now.. 'fingers crossed'.

Can these sensors be cleaned anyway ? - Just for information.