| Author | Message | ||
| Bill White (Nc_newbie)
Junior Member Username: Nc_newbie Post Number: 141 Registered: 2-2003 |
Unfortunately, these can not be repaired since they are encased in resin. You would destroy the electronics getting the resin off to get at the bad component. It would be very easy to design and build a replacement though. I could post a schematic design if sufficent interest. I don't think these are a bosche part. They were only used on Lambos and Ferraris as far as I know. (At least the ones in the pictures in this thread). | ||
| dave handa (Davehanda)
Intermediate Member Username: Davehanda Post Number: 1220 Registered: 5-2001 |
I've been following this thread and it has got me wondering...Are there any electronic service companies that rebuild these ECU's? Just seems a waste to toss these things out when it is likely just a single component failure that needs replacing on the board. I am supposing that there is little market for this, since most cars these don't fail, and only Ferrari charges huge dollars for replacements.... This one has Bosch stickers all over it, is it "generic" or Ferrari 328/Mondial specific? | ||
| Bill White (Nc_newbie)
Junior Member Username: Nc_newbie Post Number: 140 Registered: 2-2003 |
Looks like you have a bad ecu. Yes you can remove the thermole couple and put a 5 ohm resistor to the two ecu connectors to verify. Also it would be helpful to note what the resistance of your thermocouple is at room temperature. Please ohm that with a meter and post the "cold" resistance of the thermo couple. If it is really low <1 ohm you should probably crank the car measuring the resistance as it warms up to make sure the thermocouple is ok. You don't want to put a new unit on a defective thermocouple or you might kill it. | ||
| Tillman Strahan (Tillman)
Member Username: Tillman Post Number: 786 Registered: 11-2001 |
Bill, do you mean replace the thermocouple with the resistor to verify the ECU? Or can I just pull those two wires off the ECU and put a jumper with the proper resistor across those terminals? Thanks | ||
| Tillman Strahan (Tillman)
Member Username: Tillman Post Number: 784 Registered: 11-2001 |
Follow up. Yep, that's the reason it doesn't work. Reattaching it results in a slow down light that's always on. Off to the archives for suggestions, but my first guess is a bad ECU. Does this sound reasonable? | ||
| Tillman Strahan (Tillman)
Member Username: Tillman Post Number: 783 Registered: 11-2001 |
Thanks for the help. I opened up the passenger side panel in the trunk and found a disconnected coupling. The wire colors on one side match the desciption in Bill's post, and the other side of the coupling runs into a yellowish brick. I believe this means the ECU is actually disabled. Before I reattach this wire, can you all verify my thinking? Pictures are attached below, I apologize for the quality.      | ||
| Bill White (Nc_newbie)
Junior Member Username: Nc_newbie Post Number: 138 Registered: 2-2003 |
I'm not exactly sure which 328 models corespond but I do know that I have a 328 wiring diagram that matches my 3.2 mondial exactly for this entire system. I've heard different people say that there is no feedback to the FI system. However when I was having problems with mine I could make the light go on and off by opening and closing the throttle microswitch by moving the throttle slightly. When my light goes on it feels like the mixture leans out because I get a little bit of poping and overall power seems low. There is a diode on this wire before it goes to the FI ECU. I have actually thought about designing a better cat ECU and selling some of them. I see now they are about $700 now and I could build them and sell them for a fraction of that and they would not go out. Bill | ||
| Steve Magnusson (91tr)
Intermediate Member Username: 91tr Post Number: 1951 Registered: 1-2001 |
Bill -- In your post you describe that set-up/harness wiring colors as being "also used on the Mondial 3.2 without ABS" -- but what's the other model? -- 328 without ABS per Tillman's car? It's interesting to note that the version you describe has some (safety?) feedback to the injection ECU when things go wrong. The TR has a more primitive system where an audible buzzer sounds when either warning light comes on, but there's no connection/effect to the injection control system(s). Here's the corresponding harness (not ECU) wire colors/functions on the 4-pin (US version) TR warning light ECU set-ups: 1/6 bank pin 1 = green/white = +12V power pin 2 = green = to the 1/6 slow-down warning light and buzzer (ground to turn-on/test warning light) pin 3 = black = ground pin 4 = not used 7/12 bank pin 1 = green/white = +12V power pin 2 = red = to the 7/12 slow-down warning light and buzzer (ground to turn-on/test warning light) pin 3 = black = ground pin 4 = not used | ||
| Bill White (Nc_newbie)
Junior Member Username: Nc_newbie Post Number: 134 Registered: 2-2003 |
There were a few different versions of the ecu that controls this but the one I am familiar with I can explain how to test. The one I am familar with was also used on the Mondial 3.2 with out ABS and is white/yellowish in color. It is located in the trunk and has four wires. The color of the wires coming out of the ECU to the connector is a different color than the harness wire colors. The harness wire colors are the following: Black - Ground Red - to slow down light (gound it to turn on light) Orange/yellow - to FI ecu and throttle micro switch Blue/black - 12V with key on So check power and gnd then ground the red wire and see if the light comes on. If so you've got a problem with the ecu or thermole couple. If you only have one thermocouple (meaning you can't switch sides) then put a 5 ohm/10W resistor in it place to verify a bad ecu. Bill | ||
| Steve Magnusson (91tr)
Intermediate Member Username: 91tr Post Number: 1950 Registered: 1-2001 |
If the self-test isn't working -- then for sure you've got a problem. You'd be lucky IMO to only need a bulb-ectomy (but we can hope  ). The usual way these gizmos work is +12V is put directly on one side of the warning light bulb and the other side of the bulb is hooked to the warning light ECU. When the warning light ECU "wants" to turn on the bulb it "grounds" the wire coming from the bulb. If you can deduce/determine which wire is going from the bulb to the warning light ECU you can unplug the warning light ecu and ground that wire directly (with the ignition key "on") -- if the bulb comes "on" you know the +12V power and the bulb are OK (and you've probably got a dead warning light ECU) -- but please verify that the 328 has this architecture as I'm not specifically familar with the 328 schematic. | ||
| Tillman Strahan (Tillman)
Member Username: Tillman Post Number: 776 Registered: 11-2001 |
I've never seen it light at all, I didn't know it was supposed to self-test. Time to check a bulb, I guess. | ||
| Steve Magnusson (91tr)
Intermediate Member Username: 91tr Post Number: 1949 Registered: 1-2001 |
Is the self-test working OK? -- i.e., turn ignition key "on", slowdown light(s) should come on for a second or two and then go out. To do a true functional test I believe you'd have to remove the thermocouple from the cat and externally heat the tip of the thermocouple to greater than something like 1500~1600 deg F (IIRC) with the ignition key "on" (the slowdown warning light "turn-on" exhaust temp spec will be listed in your OM). | ||
| Tillman Strahan (Tillman)
Member Username: Tillman Post Number: 775 Registered: 11-2001 |
Ok, so I'm paranoid about this thing bursting into flame. How do I test the "slow down" light to verify that it is working? Thanks |