OBD II operation

On my 355 and BMW I have the engine running...this also allows me to read the live sensor data streams, like intake air temp, coolant temp, O2 sensor voltages, etc.

 

My OBD II scan tool says specifically to NOT run the engine while erasing codes. Just have ignition on.

 

I think there are 2 kinds of OBD readers. One kind just pulls codes which you can erase. They tell you to do that with ignition on only. The other kind obd2 reader will monitor the engine as it is running and pull codes. With these units you can erase codes/pull codes and see engine parameters. So if your machine can see air temps and o2 voltages etc engine on. Pull codes only then ignition on engine off.

That said I have many times used a "pull code only reader" with engine on with no ill effects.

 

I have used my reader on many different cars with just the ign on to pull codes and erase them. When I used it on my friend's 355, the extra ground connection had to be added to the obd connector and the engine had to be running to read and clear codes. I think the brand is Equus innova. FWIW

Jeff Pintler
89 348tb, 86tr

 

Where do yous buy your scan tools.....ebay? Actron? Need an obd 1.......

I ubderstand you use an obd 2 with an adapter cable.....

 

scantool dot net

 

Thanks, Glass, Ill check them out. Hope they dont want $5000 for one, as I heard they go for.

 

the problem is all obd2 readers are not the same i can hook up 5 differnt readers and pull "ghost codes" or multiple differnt codes on the same car, also you cant always trust the data stream take it all with a grain of salt the other problem is that ferrari is not the most obd friendly car since they have such low output they can get away with stiffing the obd regulation. Ferrari does not want you in their cars like that "jerks". but they are not the only euro make that can fall short on the obd side, they were able to skimp on us safety airbag standards with the 430 arguing expensive to our government

 

I thought I was crazy but I noticed this too! I could not figure out why sometimes there seemed to be a lack of consistency with code reading. In fact I never trust the codes the first time I get them. I always reset and look again for codes to reappear. I have had the most consistent codes with chevys like 100% accurate. Is the car the problem or the reader? Have you found a reader that seems to be more consistent than others?

 

Nope we are in the same boat on a Ferrari I will plug everyone I own and compare

 

Interesting, I have used various code readers, both my own and friends, and have always read consistently the same with each one. Is it possible that not having the recall performed on the OBDII plug ground wire might contribute to poor or inconsistent readings?
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I am with you, it has worked well for me. BUT I had campaign 148 done because many won't even read the port without the gnd.

 

The campain had to do with Ferrari not following the rules for us obd2 pin connectors they only put a ground wire on one pin either 4 or 5 the their fix was to have us install a pin in the missing hole and with a cheap splice it over to the existing wire on pin 4 or 5. With out it some state emission inspection machines could not communicate.