| Author | Message | ||
| Byron (Bmyth)
Junior Member Username: Bmyth Post Number: 84 Registered: 10-2002 |
Good call, david...hadn't thought of that one. ;) | ||
| david handa (Davehanda)
Member Username: Davehanda Post Number: 364 Registered: 5-2001 |
Let's not forget the use of Stabilant 22 for the connections to all these ECU's. I know of a couple people who now make it an annual ritual to remove all the ECU connections, flush them with a little CRC electrical contact cleaner, then apply a dose of Stabilant 22 contact enhancer. They have solved all there running problems and "slow down' lights issues since doing this. In other words it isn't always the ECU that is bad, but the connection to it that is bad. I suppose the real fix would be to figure out some upgrade to better connectors. | ||
| Byron (Bmyth)
Junior Member Username: Bmyth Post Number: 83 Registered: 10-2002 |
Jean-Louis - sounds like you may be having a problem with your Exhaust ECU's. Check the pictures/posts below... My SLOW DOWN 1-4 light was coming on as well (no power shut-off like yours though) - I disconnected my Exhaust ECU's, problem solved. You can just either disconnect them or replace them. Just be sure to twist-tie them up so they don't get caught on anything. | ||
| Jean-Louis (Jlm348)
New member Username: Jlm348 Post Number: 28 Registered: 11-2002 |
Please Help Last week, I took the 348 Spider for a quick spin. It was about 45 degrees and the car was driving fine. Then at a stop light the slow down 5-8 came on. I was at idle, lost power, drove for a couple of blocks, turned the car of and back on. The problem was gone. This is the first time it has happened to me. Do I need to change the ECU's or is it something else that I did wrong. I do not know if I should wait for it to happen again, or is it an immediate sign that I should change them. Thank you | ||
| Jeff B. (Miltonian)
New member Username: Miltonian Post Number: 7 Registered: 12-2002 |
This problem is universal with 348's, isn't it? Is the replacement ECU exactly the same as the old one? At $250, it should last forever, not just a few years. Wish I had just unplugged mine instead of replacing them....at least I didn't pay anything for diagnosis and repair! | ||
| Dan Marlett (Ferrari_dan)
Junior Member Username: Ferrari_dan Post Number: 54 Registered: 9-2002 |
Frank, Ernie is correct, the car will run fine without the ECU. I don't have the luxury of running test pipes because I am in Texas. Put the pipes on and be done with it. The only thing different is your slow-down-dummy lights will not illuminate when you first start the car. Good luck! | ||
| Ernie Bonilla (Ernie)
Member Username: Ernie Post Number: 455 Registered: 11-2001 |
It doesn't resolve the problem is just hides it. The only thing that the exhaust ecu does is monitor the temperature of the cats. If they start to get to hot it warns you to slow down. Hence the slow down 1/4 or 5/8 light. It flashes when you get the warning if it comes on steady it will shut down either banks 1/4 or banks 5/8 depending on which light is on. I had it happen to me once before and there is a huge power loss because you are only running the engine with four cylinders as compaired to eight. There is also a pronouced change in the exhaust note. Scared the crap out of me when it happened. So on advice to get around the problem I just disconected it. I know that the ecu is bad because I switched the from one bank to the other and the problem appeared on the other side. Another thing is that the light would come on as soon as I started the car after it had been sitting for a week. So I know it is a bad exhaust ecu. Now if a car that has a good ecu is having the slow down light come on, I suggest you slow down. What is happening is that the car is running rich and the extra fuel that isn't being burned in the enigine is being burned off by the catalytic convertor which causes it to get hotter than normal. This is what will lead to the cat going bad permaturely or even worse it catching fire. I'm willing to bet it is your ecu that is bad and not the latter. | ||
| Byron (Bmyth)
Junior Member Username: Bmyth Post Number: 68 Registered: 10-2002 |
So disconnecting the exhaust ECU's resolves the problem of "Slow down 1-4"? I've seen that appear a few times - if left connected, does it affect performance? I don't have the cat bypass pipes, but rather, punched cats....hmmm, will I run the risk of catching fire? | ||
| Ernie Bonilla (Ernie)
Member Username: Ernie Post Number: 454 Registered: 11-2001 |
I can tell you for absolute sure, that if you disconnect the exhaust ecu that the car will still run, and with out the light coming on, or the engine shutting one of the banks down. I know this because I currently have the left one on my car disconnected until I decided to buy the new ecu. The only problem is if the cats get too hot you risk ruinning them, and also have the risk of them catching fire. But seeing as you are going to run the bypass pipes you won't have that problem. | ||
| Martin - Cavallino Motors (Miami348ts)
Advanced Member Username: Miami348ts Post Number: 3453 Registered: 5-2001 |
Frank, mine did that too for a while. Stopped at one point. Actually thinking back since I put the by-pass pipes on this is gone. | ||
| Frank Bussi- Sottile (Caruso348)
New member Username: Caruso348 Post Number: 19 Registered: 5-2002 |
Dan you da Man; One more question if you don't mind. I'm installing cat bypass pipes and will disconnect the ECU's. Do you think that the slow down fault might still engage, even if the ECU is tied off somewhere on the frame? Thnaks again. | ||
| Dan Marlett (Ferrari_dan)
Junior Member Username: Ferrari_dan Post Number: 53 Registered: 9-2002 |
Frank, it is the ECU for the thermocouple for the cat. I had the exact same symptoms and recently replaced the ECU and the problem was solved. I am 100% positive this is the problem. It�s very common. The part is about $260.00. Good Luck! | ||
| Frank Bussi- Sottile (Caruso348)
New member Username: Caruso348 Post Number: 18 Registered: 5-2002 |
Just yesterday with about 30 minutes of running time Slow down 1-4 illuminates and loss of power is experienced. Needless to say I freaked. Continued driving, with seemingly half an engine running, until I could exit highway. Shut the engine down and restarted. Everything back to normal, no more faults for the rest of the day. This has happened twice in the past couple of drives. Any comments or suggestion? | ||
| Rexrcr (Rexrcr)
New member Username: Rexrcr Post Number: 26 Registered: 11-2002 |
I had access to all of Ferrari's oem resources when I was part of the Company at an Authorized Dealer. I may be able to come up with what you're looking for ('box procedure). I think what we all (348 owners and fixers) are experiencing is the phenomenon of when the cars were new the Dealer network, FNA and Ferrari, SpA were involved and motivated to repair while under warranty. So many if not all were properly repaired. I personally repaired a buy-back lemon-law car and turned it into Challenge config. Yes, it took a few sprinkles of Holy Water and a couple of man-weeks to fix, but then it ran reliably for years and won a couple of races. Now, the repair info is a bit more difficult to find. I strongly believe that the wiring problems can all be solved, though some will take a week of work (40 hours+) to diagnose. Yes, I've had my share of bad pin connectors, but maybe you're right, rewiring, as these cars age, may be the simplest solution. It's a prety radical repair solution, doesn't actually tell you what exactly was wrong. I'd stick with OEM harness to save time. | ||
| Mark McKenzie (Redcar)
Junior Member Username: Redcar Post Number: 127 Registered: 4-2001 |
I had a "fluttering" 348 misfire that worsened at certain rpm's, and always felt down on power, although it was smooth as silk at other rpm ranges. Turned out to be a plug wire, diagnosed luckily, while watching the engine run at night and I noticed the arcing wire. Might be worth checking. Mark McKenzie | ||
| JRV (Jrvall)
Junior Member Username: Jrvall Post Number: 227 Registered: 11-2002 |
Check all plug wires easily with an ohm meter( radio shack, sears, etc.). one test lead in each end of plug wire while gently flexing, jiggling the wire...resistance should remain constant while movement is induced...if resistance flucuates wildly likely a bad internal winding. For the best plug wire info, go to www.magnecor.com ... I use his wires on all Diablo's and many other applications. Missing can also be bad injectors or loose/dirty injector connectors...yes the plug-in connectors are crappy in the real world of use (i guess it looked good on the drawing board) the tiny pin slip connectors can become loose, dirty, corroded, bent, and the thin section wires often get pinched almost thru during original manufacture. The best way to track a loose/poor/bad connection that I have found is to first...with the engine running...jiggle every connector, one at a time, many times in this way you can induce a problem, anomoly, clitch to come and go, second..if procedure 1 doesn't reveal anything, start pulling the connectors one by one, starting with those that vibrate the most or have their loom dangling, with a flash light & manifying glass throughly inspect the internal pins....then gently fold back the rubber weather protector and check from the back, especially where the wire is crimped for excessive pinching...also insure each and every pin is firmly secured into the plastic socket. I have solved quite a few gremlim problems by carefully and methodicaly going thru these connectors and eliminating problems of one sort or another. A side note...if the cats are overheating, it's because excess fuel is being dumped into them...while you may not care about gassing your nieghbors...that excessive fuel is ruining your engine by washing away lubricating oil neccesary to keep the rings and valve guides from wearing out very prematurely. | ||
| billy bob (Fatbillybob)
Junior Member Username: Fatbillybob Post Number: 78 Registered: 8-2002 |
REX If you have breakout box multimeter reading for the ECU will you share with FC? How did you get them? | ||
| billy bob (Fatbillybob)
Junior Member Username: Fatbillybob Post Number: 77 Registered: 8-2002 |
Rexrcr, This is a huge problem. You can see the crappy 348 wiring diagram. That is one issue. Second issue is you can get no values for the breakout box. Ferrari has a secret or does not know the values. Third issue is that the connections in the 348 are so bad that even with a breakout box you can still get faults since you may have a good connection of wiring harness to breakoutbox to ECU but when the Wiring harness is on the ECU anything can happen. The 348 footbed fuse box is an absolute POS. The 348 will fool you. For example, I have an interesting situation that no one can solve at this time. I swear it is an electrical problem probably in that crappy fusebox. There is soemthing preventing the ECU's from adding in fuel on cranking. I get a lean crank condition causing no start that is solved by adding fuel up stream of the hotwire sensor. Once the car fires once it is fine. Every circuit checks out as does all mechanical systems of basic spark and fuel. However, there is an electronics glitch somewhere in the wiring harness and it is not the ECU's that is an absolute. One day I'll take it circuit by circuit but it is just easier to dump in some extra fuel. Besides it is a great anti-theft device!!! The best thing you can do to a 348 is to re-wire it custom. It will be a lot better and much lighter. To solve the potting issue on the exhaust ECU's just use epoxy and add new hard potting. The seal is then intact. Infact all Ferrari connectors should be hard potted. I'd do that first in a re-wire job. i have gutted a 348 interior for racing you should see the wiring OEM. It is a crime. It screams out for a re-wire it is so stupid. | ||
| Ernie Bonilla (Ernie)
Member Username: Ernie Post Number: 444 Registered: 11-2001 |
Thanks for the info Rex. I guess I'm just gonna have to caugh up the dough and have the misfire found, seeing as I don't have equipment or the know-how for diagnosing the ECU. | ||
| Rexrcr (Rexrcr)
New member Username: Rexrcr Post Number: 20 Registered: 11-2002 |
I think I posted this info on another thread, so forgive me if I'm repeating. There are at least three generations of Thermocouple ECU's. The only one worth owning has a relatively "soft" potting material. You can tell the difference easily by pushing your fingernail into the potting (the concave portion, the part described as pulling away from the housing in earlier posts). If your fingernail can push in slightly, it's the latest design. If it is rock hard, older one. Also, install the new one with a couple of washers between the ECU and the frame on each stud. This problem is a frustrating gremlin to exorcise from the car, but can be done. There can, of course, be other causes to the misfire. I doubt there exists a better plug wire than OEM. The problem solving methodology for misfire involves a detailed engine ECU pin test using a break-out box. One critical value is the resistance in the Lambda (oxegen sensor) circuit ground to be less than 2 ohms. | ||
| Chris Richardson (Boozy)
Junior Member Username: Boozy Post Number: 231 Registered: 11-2001 |
I have not replaced the bad ECU, since I know what is wrong I just unplugged it. That is exactly what happened, it shut down 1 bank so I was running on 4 cylinders. I have also since put in test pipes so I shouldn't have to worry about it anyway. I will eventually replace the ECU just to have the car perfect. I believe that they are about $250 each. I have seen them on Sodacom's so they shouldn't be too hard to find. | ||
| Ernie Bonilla (Ernie)
Member Username: Ernie Post Number: 402 Registered: 11-2001 |
I have thought about the plug wires, but I don't want to start replacing things that don't really need to be replaced. I would rather diagnose the problem properly first, then replaced or repaired what needs to be fixxed. Because you all know how much of a rip off the parts are for these cars, and if I get in the practice of spending money on parts that really don't need replacing, it will be waisted time and money, and I will still have the problem. So is there any type of test I can do to see if it is the wires that are bad? How ever, I'm wondering if there are some after market plug wires that are better than the factory ones? If so which ones are best for the 348? | ||
| Fred (I Luv 4REs) (Iluv4res)
Junior Member Username: Iluv4res Post Number: 197 Registered: 8-2002 |
Ernie, Perhaps it is your spark-plug wires. If those are bad, it will cause sputtering while accelerating. | ||
| Ernie Bonilla (Ernie)
Member Username: Ernie Post Number: 401 Registered: 11-2001 |
Thanks Gene I know what your talking about because I have already switched both of the exhaust ecu's from one side to the other. After I did that the slow down light showed up on the other side, so now I know which one it is. Now I'm just trying to find what is causing the misfire in my car. It's really wierd cause if I short shift under 2,000rpm, through all the gears, I don't get any misfire. But once I get into the 2,300-3,900rpm range, no matter what gear I'm in, the engine is popping, hesitating, and misfiring big time. But if I get the engine speed in the 4,800-6,500rpm area the car runs like a champ. Then around 7,000rpm the problem comes back. Also sometimes after I have driven the car for awhile, when I restart the car the misfire changes from one rpm band to another. I can shift normally at 3,000rpm all the way up to around 4,000 rpm without the car hesitating, and misfiring. But then from about 4,200-6,500rpm the problem is there again. I'm not sure if it is computer related or something with the wiring. I'm leaning towards the computer, but WHICH one? | ||
| Gene Agatep (Gagatep)
Junior Member Username: Gagatep Post Number: 52 Registered: 8-2002 |
Ernie, In disconnecting the Cat ECU's there are 2 sets of leads per ECU. Disconnecting the small one which has two wires will not bypass the ECU Slow down problem. Disconnecting the larger connector will bypass the ECU Slow Down problem. Or Else, disconnect both if you don't understand what I'm talking about. (See the picture on the thread below) | ||
| Ernie Bonilla (Ernie)
Member Username: Ernie Post Number: 398 Registered: 11-2001 |
Right on Frank, thanks I'll try that and see what happens. | ||
| Frank Parker (Parkerfe)
Intermediate Member Username: Parkerfe Post Number: 1489 Registered: 9-2001 |
Ernie, I wouldn't think so as the thermacouplers and cat ECUs are only there to warn you if a cat is overheating. Try disconnecting both thermacouplers from each cat ECU and see if the misfire goes away. If it does, reconnect one at a time to issolate which one is bad. If the engine misfires which both thermacouplers and ECUs disconnected, then the problem lies elsewhere. | ||
| Ernie Bonilla (Ernie)
Member Username: Ernie Post Number: 396 Registered: 11-2001 |
Frank will a bad thermocoupler cause a misfire? Is there any test I can do, other than replacing them, to find out if that is the problem for sure? | ||
| Frank Parker (Parkerfe)
Intermediate Member Username: Parkerfe Post Number: 1483 Registered: 9-2001 |
If you still have the Cats on your car, it is most likely the thermcoupler rather than the Cat ECU . In that case, I would go ahead and replace both thermacouplers. If you have test pipes, you can disconnect the cat ECUs altogether. | ||
| Dan Marlett (Ferrari_dan)
New member Username: Ferrari_dan Post Number: 32 Registered: 9-2002 |
Chris, I am experiencing the similar light coming on and the car sometimes seems to run on 4 cylinders. Did yours do this as well? What did the Exhaust ECU run? This happens when the car is cold, when did you experience it? | ||
| Ernie Bonilla (Ernie)
Member Username: Ernie Post Number: 395 Registered: 11-2001 |
Hey guys, I was having the same problem with my 348. So I switched the two exhuast ECU's that where mentioned and I got the problem on the other side. Now at least I know which exhuast ECU is bad. How ever I was also having a misfire problem and was hoping that the bad exhaust ECU was the problem. So as Billy suggested I unplugged the bad one and the car still ran, but it didn't get rid of the misfire. I had a new set of plugs put in. I have switched the ECU's behind the seats in the cabin from one side to the other with no luck. I also have swapped the coils from one side to the other with no luck finding the problem. Any advice as to what it could be, or what to do to find the misfire? I have found out that these cars aren't difficult to work on and now that I know this I really don't wanna take it to my mechanic. Besides it seems that the problem is just something electrical and if I could just find it I will fix it myself. | ||
| billy bob (Fatbillybob)
Junior Member Username: Fatbillybob Post Number: 55 Registered: 8-2002 |
Chris, Just un plug it and see what happens. Prove it to yourself. The only problem is you have to know your car. If it feels funny check things out. The ex ecu shuts down the car if there is a cat temp too high that cna cause a fire. That is the only funtion. | ||
| Chris Richardson (Boozy)
Junior Member Username: Boozy Post Number: 217 Registered: 11-2001 |
I swapped them and sealed the one which was giving the error, it did have some space around the edges. I only had the error once for a short time since then with the same ECU, now on the other bank. Hopefully there won't be further problems. Can you seriously just take them off? I don't think I would go that route but would it work? Thanks so much for the pictures! It made them super easy to find! | ||
| Dave Penhale (Dapper)
Junior Member Username: Dapper Post Number: 246 Registered: 4-2002 |
Julian, I think they are talking Exhaust thermocouple ECU's (admittedly poorly referred to as its not 'C'ontrolling bugger all, its monitoring) rather than Engine management ECU's. | ||
| Steve Magnusson (91tr)
Intermediate Member Username: 91tr Post Number: 1104 Registered: 1-2001 |
(Unfortunately) there are multiple ECUs (ign., inj., thermocouple, AC, etc.) on the later cars to go haywire so "ECU" doesn't describe a single item. I think my wife's Jeep GC even has an ECU for the turn signals! | ||
| Julian Pham (Julian_blk348)
Junior Member Username: Julian_blk348 Post Number: 106 Registered: 4-2001 |
I always thought that "Slow Down" light comes from the thermocouple signal (a bad thermocouple or the cat is too hot) and the "check engine" light is an ECU problem. Sounds to me like you have a thermocouple problem and not ECU! | ||
| billy bob (Fatbillybob)
New member Username: Fatbillybob Post Number: 50 Registered: 8-2002 |
Unplug them. You don't need them. They only real function is to shut the car down if there is fire potential. Based on how well these work I would not count on them. Ferrari Exhaust ECU's are like an empty fire extinguisher! | ||
| Bruce R. Morehead (Brm)
New member Username: Brm Post Number: 4 Registered: 4-2002 |
Chris. Before remounting the good ECU's, Coat them with 3M Ruberized Undercoating. Usually they go bad from water getting in when the plastic case separates from the encapsulation over time. The undercoat will help seal them. | ||
| Chris Richardson (Boozy)
Junior Member Username: Boozy Post Number: 216 Registered: 11-2001 |
God bless you kind sirs! Thank you so much. It's a piece of cake now! | ||
| bob snow (Resnow)
New member Username: Resnow Post Number: 27 Registered: 5-2001 |
Chris, Here are some photos I just took to help you locate the ECUs. Bob  right side ecu  left side ecu  left side ecu closeup  ecu (ref #37 in Dave's scan) | ||
| Dave (Parts_man_soda)
New member Username: Parts_man_soda Post Number: 16 Registered: 8-2002 |
 Here is a scan from my parts book. This may help you. #37 Dave www.sodacoms.com | ||
| Chris Richardson (Boozy)
Junior Member Username: Boozy Post Number: 215 Registered: 11-2001 |
I am having that dreaded Slow Down 5-8 problem and I'd like to swap my ECUs to determine if one is defective. Is there any way someone could snap a pic of one so I can figure out what they are? I can't seem to figure it out. Thanks! |