ECU repair P1117 O2 heater circuit

Dear Ron:

Congrats on getting only 2 "not ready's" after only an hour of driving. At least one of those tests requires a cold start, so in Houston, you usually only get one chance per day to get that system "ready." There's a complicated EPA drive cycle somewhere, but if you're down to 2 not ready's, you should be fine.

That's odd that the scanner didn't clear the code. As far as I know they emissions test as follows:

1. check that the MIL comes on with the key,
2. check MIL goes out after starting,
3. Check that all continuous monitors are "ready",
4. for MY 2000 and earlier, check that not more than 2 non-continuous monitors are "not ready".
5. Check the fault codes but only fail if it lights the MIL (strange, because one would think P1117 would set the MIL. Did it ever? This is where I'm unsure if you'll have a problem.)

Hope this helps....Regards.... Mark.....

PS....I use an Elm327 generic scanner that plugs into the usb port on a laptop. It does real-time monitoring like Jim's. But, of course, it doesn't work on my pre-OBDII 456, which has it own OBD that uses flashing CEL's.

 

Ferrari has a drive cycle TSB. I have not seen TAZ's key on off thing before and don't know how that would aid in drive cycle and LBM reset. What I have found that works 100% on 2 550's is to discover you own drive cycle in your area roads. I have a circuit that I run that has a loop around my area with city and freeway driving and multiple stops. When I make that run 100% all monitors are st ready. Take notes on how you set your drive cycle and develop your own drive cycle for you. Start with the Ferrari TSB and go from there.