So Today I went to smog my newly aquired 96 850 turbo. I bought the vehicle in another state from where I live. When the lady at the smog place connected the machine, she said the vehicle will show an incomplete. She showed me the machine whichshowed that there were a few things that were not registering such as the two oxygen sensors, the catalyst and one more thing,I forget. She then stated if I have more than two things not registering the computer will show an incomplete and basically fail. So she started to say I could take the car over to auto zone and have them scan the vehicles computer for codes. but to her surprise the car passed. So my question is should I go to auto zone and have them scan for codes, or maybe she doesnt know much about Volvo's. my car is not showing any messages. any thoughts.
Thanks Rob

 

Hi Rob,
She's talking about the state of readiness with regards to the sensors that are monitoring different systems in your car. I just ran through this headache with my 97 850 and while researching it I found a few threads where 96 owners had the same experience as you. They had more than the allowable number of sensors not ready (two as she mentioned) but the inspecting equipment passed the car. I'm guessing this is an acknowledgment of sorts that the 96 year volvos can be difficult to get the monitors to a state of readiness.

If the sensors are not ready they will not report a problem (check engine light) so you wont know by the looks of things that you have a problem.

You can go to autozone they will scan your car for free, they may or may not have a scanner that will tell you if your monitors are ready. I bought a Innova 3100 scanner with this feature to keep an eye on my monitors.

If you do a few searches for drive cycle you'll see the involved driving cycle you have to put your car through twice to bring the monitors to a state of readiness.

There's a few reasons why your monitors might not be up, if the battery has been disconnected for a period of time I believe that wipes out the ECU or if someone manually reset the system with a scanner that will also clear the codes and make the monitors read not-ready.

Hope this helps.
-Rob

 

You can get the codes read if it will give you a sense of peace of mind.. I would consider investing it a decent code scanner so you can read the codes yourself. It will only be a matter of time before you need to diagnose a check engine light on this car, or another one of a friend, family member, neighbor, etc....