| Author | Message | ||
| Malcolm West (Ferrari_uk_tech)
New member Username: Ferrari_uk_tech Post Number: 42 Registered: 7-2003 |
Did your repair shop test the car on the Ferrari SD2 tester ? You may well have a faulty ECU giving out intermittant readings for the 02 sensor when in fact there is nothing wrong with it. MW | ||
| Charles Barton (Airbarton)
Member Username: Airbarton Post Number: 696 Registered: 11-2002 |
Yes, I would check all connections you can get to. These cars are notorious for having bad grounding and bad connectors. Make sure all connections have been cleaned with some sort of contact cleaner. One other thing. I had the same problem once after I replaced an O2 sensor. It turned out to be a sensor that was bad from the factory. I took it back and exchanged it for another and the problem went away. Don't forget to reset motec after you are done cleaning everything. Good luck! | ||
| Lou Papaleo (Papaleo1)
New member Username: Papaleo1 Post Number: 35 Registered: 6-2002 |
Charles - I am having "Check Engine 5/8" warning light problems with no loss of performance. Ferrari has donwloaded my codes at every incident. The O2 sensor was at fault each time. We have had 2 O2 sensors and the light still comes on intermittently. Last visit found a loose ground wire so it was tightened and another strap was added. . . the light came on within 4 hours of service! Today I started her up and the light came in instantly. About an hour later, it turned itself off. I think it is just a Ferrari gremlin! Any futher thoughts or suggestions? | ||
| Charles Barton (Airbarton)
Member Username: Airbarton Post Number: 692 Registered: 11-2002 |
Are you refering to the check engine or the slow down light? If it is the slow down light, it is there to warn of an overheated catalytic converter. If the sensor detects a hot cat it will send a signal to the Motec that will cut power to the fuel injectors of that side of the engine. If the light comes on and at the same time you notice a significant drop in perormance, that is what is happening. If on the other hand the light comes on with no loss of performance, you probably need to check out the cat ECU. The casing has a tendency to crack as they age exposing the inner electronics to moisture. Sometimes all you need to do is reseal the case and the problem will go away. Of course you could also replace the ECU to solve the problem. If it is the check engine light, there are a number of things that can cause it to come on so you should do as Rob has suggested and download the code before you reset. Resetting usually solves the problem though. The Motec stores error codes that resetting will get rid of. There is one other possibility. You may have a connection problem. I had the same thing happen on my 348 that turned out to be the connection at the crank sensor. The problem eventually resulted in the engine running really bad. I tried to figure it out myself but had no luck. I took the car to the guys at FOA and they discovered the wires going to the crank sensor were barely hanging on the connector. | ||
| Lou Papaleo (Papaleo1)
New member Username: Papaleo1 Post Number: 34 Registered: 6-2002 |
That's exactly the problem - NO ONE seems to know for sure. . . it is really a hit and miss kind of situation. I've heard that even FNA has said to not worry as long as the engine is running properly. That, of course, just assures them future revenues from parts and service! | ||
| Mister Jones (Davey_jones)
Junior Member Username: Davey_jones Post Number: 104 Registered: 9-2002 |
Mmy 5/8 light came on before I removed CATS & installed test pipes. Has not returned - not sure if due to cleaning of O2 sensors and ground strap though... | ||
| Lou Papaleo (Papaleo1)
New member Username: Papaleo1 Post Number: 33 Registered: 6-2002 |
I have the same intermittent problem with 5/8 on my 355. It was diagnosed as an O2 sensor, changed twice. Both times the light has returned. Today it was in and they found a loose ground wire and added a grounding strap. Light off. . . until this evening!! What gives with this??? Any suggestions are appreciated. Anyone know where I can get an alternator? OEM is $900! | ||
| Mister Jones (Davey_jones)
Junior Member Username: Davey_jones Post Number: 103 Registered: 9-2002 |
I definately agree with Rob on this one. Could be something very simple... but why take the chance? Besides, it will bring you closer to better understanding your wonderful car  | ||
| Rob Schermerhorn (Rexrcr)
Member Username: Rexrcr Post Number: 773 Registered: 11-2002 |
JRK is correct on how to reset. But the first step is downloading the code or codes and see what's up. Ignorance is not bliss. It's expensive. Search... | ||
| J R K (Kenyon)
Member Username: Kenyon Post Number: 613 Registered: 10-2002 |
Disconnect the battery from the car. Then reconnect. Let car idle for 10 mins to reset ECU. The light should be out and wil not come back on. | ||
| dave handa (Davehanda)
Intermediate Member Username: Davehanda Post Number: 1565 Registered: 5-2001 |
Lot's of info, if you search the archives. | ||
| JOSEPH MAURO (Joe348ts)
New member Username: Joe348ts Post Number: 5 Registered: 8-2003 |
What Does it mean and how do I shut it off? 91-348 |