Hi, Have had an intermittent problem of one of the cylinder banks (as i only have one SDL sourcing the bank) it was the right hand bank / exhaust (looking from the car forward) that was cold.... My question is what does the Motronic ECU (5.2) 'cut' to shut down the bank. I will then use the relays and fuses as switches to see what is at fault. I have swapped the Motronics from left to right and the problem seems to be the same... I have disconnected the Catalyst Control Units to remove them from the chain of diagnostics, these are fine. This is a really dull question from the diagrams and schematics i have of the engine, does the (looking from engine bay) left air box and intake feed the right cylinder bank, if so is the ECU wiring configurred for diagonla control e.g left air flow meter working with information from right cylinder bank?, and which Motronic ECU controls which side....i.e Motronic unit controls the cylinder bank in front? Any assistance greatly appreciated.....or guidance on a testing route would be welcome!. Thanks.
Hi Nigel, Sorry for your troubles and I'm not going to be of much use to you save only a "bump" of the thread I'm afraid. The only commonality I can see in your question and my experience of the 360 relates to the diagonal question. I recently discovered on the 360 that the wiring loom from the ECU for bank 1 (1~4) crosses over and connects to the MAF and throttle on the opposing side. At certain RPM there are secondary valves open in the inlet manifold which effectively mean that the right hand bank is fed from the left (while at other RPM the opposite is the case). As to what is cut when a bank is shut down - I can only surmise that it must include fuel at the minimum (to protect the Cats) but maybe more. Best of luck with your diagnosis and repair!
Thanks for the reply....the V Engines can be damned confusing when looking at a schematic!!! Back to the tests on possible causes : Update : I have removed the relays for the fuel pumps, and jumped the connections to test if the fuel pumps work....they do. No issue on fuel pumps. On innitial start up, cold engine, both banks fire up, can be driven.....on stop and restart the LH BANK (as per fuse table) is not firing. If i remove the RH FUEL PUMP fuse, this forces the LH FUEL PUMP to operate alone and the car fires up on 6 cylinders, replace RH FUEL PUMP FUSE 12 cylinders firing. Turn off engine, and restart LH not firing again. Tried same test but pulled relays instead, same results. Tried the test with injection relays, same results, system FORCES a LH start with no RH INJECTION relay, RH replaced system fires on 12 cylinders. Tried same test with LH and RH ECU fuse......with RH fuse removed, no firing at all, is this the Master Slave relationship of the Motronic unit eg , if no RH found, give up, if RH found but no LH found start on what is available? I will re swap the MOTRONIC ECU's to see if the system still persists on LH BANK......(see if ECU issue) if no change Step 2 Next test is the MAF sensors - Swap......
Sounds like you've pretty confident on test possibilities and have already explored a quite a few! Well done on that. I find it weird (and very interesting) that doing something like disabling the fuel pump on the happy side can can effectively tell the system to ignore an error from the bad side and start anyway. You previously mentioned something I didn't understand - something about only one SDL sourcing the bank. Care to elaborate on this - someone with knowledge may chime in? Also, I presume you can't extract any trouble codes from either ECU?
the 456M GTA has two Motronic 5.2 ECU's, buthe SLOW DOWN LIGHT in the dash is common, so as a driver you have no idea which back is giving you trouble... The older cars has a light for each bank...much easier and user friendly... The common man solution....sprinkle some water on the exhaust manifold, which ever gives more steam is the working side.....saves unplugging connections to listen for idling changes! Hardly rocket science...but it works!
For your first question; in the 550 WSM manual in the injection/ignition section, it states that the Motronic cuts power to the injectors to shut down a bank. It's silent about whether the ignition continues to spark. There are a couple of statements you made that are a bit confusing - perhaps you could explain? You said you had a SDL on one bank, but you "disconnected" the catalyst ECU's and "they were fine?" (This is odd because the Motronics need to see signals between 1.00 and about 3.0 volts from the catalyst ECU's to know they're healthy. If a catalyst ECU is disconnected, or its thermocouple is disconnected, I think the Motronic will probably shut down that bank.) Also that you swapped the Motronics from side to side but the problem was the same (meaning it stayed on the same bank, and didn't move when you swapped ECU's?) Without knowing more, it seems like a catalyst ECU has triggered the SDL, set a CEL, and shutdown a bank. You can simulate the presence of a healthy catalyst ECU with a 1.5v source, and feed this back to the Motronic, reset the CEL Motronic with some OBDII software or by resetting the ECU with the battery disconnect switch and retest. Or reset your CEL's, etc., swap the catalyst ECU's, and see if the other bank goes cold. If/when bypassing the catalyst ECU's with a 1.5v signal be very careful in case there was a "real" reason one bank was shutdown.
hi. thanks for the info on what is shutdown....its another circuit to test. to clarify.....i have a thermocouple failiure, which was diagnosed via a continuity test on ther ECU plug... disconeecting the ECU with the three pin plug (not the thermocouple) shows a slow down light, but does not shut down any engine banks. de catted ferraris use the same trick and sometimes remove the SDL light. i did swap the motronics units and am pretty sure the same bank was not firing....i will re swap and check the findings, i swapped ECU's, fuses and god knows what else so confusion was getting to me. bizarely enough tested the car an hour ago, all fired up, quick 5 min drive, turned off the engine, then re started, and only 6 cylinders fired. must be a heat / connection issue.....not sure if that deepens the mystery or actually helps in that its not a permanent "non fire".... i dont think its a set CEL issue, as i have disconnected the battery overnight and allowed the reset ECU procedure to run... Catalyst issues are removed from the chain....but i will try the 1.5v hook up.
A perplexing problem indeed Nigel. It sounds like you may have to get down and dirty with individual connectors, pins, sensors to get to the bottom of this. Good luck and do please post your further test results etc. You're bound to "ring a bell" with someone!
Yea, now that you've clarified the process, it seems one of the t'couple's feeding a catalyst ECU is the culprit. Interesting, I had one of my 550's catalyst ECU's disconnected and thought I remembered it was running on only one side, but that was last October and I've slept since then Dodgy thermocouples and their connections are a very common issue, not just in automotive electronics. They're one of the most common faults maintenance teams deal with in the petrochem industry. As you say, it now doesn't sound like the catalyst ECU's themselves are at fault, but one of the thermocouples feeding a catalyst ECU. If you've already swapped the catalyst ECU's and the main ECU's from side to side and the problem stayed the same, that points pretty conclusively to the t'couple on that bank. Bypassing both the thermocouple and its catalyst ECU with the 1.5v signal will prove it.
all ECU's and Thermocouples disconected..... no reset procedure undertakne, batetery left connected. 1st start this am....12 cylinders and only 2 gears - Autobox 2nd and Reverse.... turnd off, re started - 12 cylinders ALL gears.......(with slow down lights....but that was expected) turned off and restarted....6 cylinders and only 2 gears and ASR on the dash....i think the ASR is a symptom of low voltage or voltage drop on startup....the battery is fine, fully charged, on a tender overnight...but the 3 quick starts might have had an impact. I am leaning towards a check circuit in the system....posibly one of the Motronic ECUS's... Once your on the path......there is no jumping off.....not wihout a lottery win and ship to a dealer!!! everything is pointing towards the Motronic ECU's as they are the @brain' for left and right and control all manner of down power controls. Can someone confirm that the Mottronic ECU copuld possibly impact the AutoGearbox? as in cut it to limp home mode, depending what the motronic thinks is a problem....
Have a read of this thread, it may be of use to you. http://ferrarichat.com/forum/showthread.php?t=328364
Update.. After reading as many threads and posts as possible for the issues.... Bypassed the cat ecu by sending a 1.5v on teh trigger wire back to the Motronic ECU and stopping the slow down light ( as this is purely to see if teh damned car will consistently start on 12 cylinders and hopefully all gears the issue of overheating cats is not a concern) Anyway, SLOW DOWN LIGHT extinguished...good result... still 6 cylinders, pulled the Motronics out and had a close look at the connections, one of the pins in the connector was badly corroded, looks like water ingress at some point, calcification etc... Bosch offer an electronic repair service for the Motronic ECU's, need shipping to Germany...have to go through the Bosch dealer network...not a problem.....but oh yes it is...can i find an authorised Bosch distributor....YES!, will ANY OF THEM take on teh shipping of the part....NO!....so i know i can get it repaired and refurbished...i knbow where to get it refurbished, i know how i have to get it there...but not one Bosch approved garage will touch it.....frustrated doesnt cover it!!! Arggghhhhh!!!...... Untill that is resolved not sure if the rest of my issues, 12 cylinders intermittent limp home mode gearbox may be part of the same problem..... You can nver second guess Italian and Ferrari electronics and there safeguards!
Odd that the one bank still isn't firing even with the slow down light resolved. Before sending a Motronics ECU off anywhere, I'd swap them to see if the problem follows the swap. I know that you've swapped them once before but that was while the catalyst ECU issue was still active. It might be useful/interesting now to swap them again. Don't forget to let them relearn before giving it the stick....
yes once the ECU and SDL was resolved the Motronics were swapped and the issue foilloed the motronic...there must be a master slave scenario with the unit as if the motronic with the issue is (on a RHD drive car ) in the passenger footwell LH..car fires but only on one bank, if the suspect unit is in the RH footwell the car takes agges to fire up, as it seems to try and force the RH to fire up and then think sod it lets try the LH bank... Anyone have any ideas on this???????????
You should change out both ECUs. If one has gone bad, the other cannot be far behind. Buy new ones. BTW, when the car goes into limp mode, it shuts of the ignition and the fuel to that bank.
Did you see this post regarding Bosch repair service in Germany: http://www.ferrarichat.com/forum/showpost.php?p=140990814&postcount=15 Maybe the same place used by the poster (link in post) will be willing to send your units in if you send to them...? The poster had a 456 with what seems like similar symptoms. Jes
If the ecu's have gone bad, you don't need to buy new units, just replace the bad eprom/s in the existing units. Have someone burn you a set with the proper programming and then swap them out. Or you can do what joakim did, in this thread http://ferrarichat.com/forum/showthread.php?t=342305&highlight=456+ecu
Mnaged to get a contact email for Bosch in Germany, who offer the electronic repair service. They are willing to operate outside of the dealer network on this request, send item direct...with LOTS of insurance!!! on postage. See what phase II brings with tested and repaired ECU's! Hopefully all issues fall back on this element, as its a pre check item i hope so. Currently suffering from ASR light on in dash Limp home gearbox (2nd and reverse only) 6 cylinders on startup after warm, or over three sequential starts in quick succession (DEFINATELY ECU)
Had the corroded pin on the ecu repaired....have swapped from side to side...fault no longer follows ECU...one problem eliminated, new battery and fully charged before install, second problem eliminated. engine will fire up but only on 6 cylinders bank 1-6....can get 7-12 to fire up if i remove the 1-6 fuel pump fuse (swapped all relays no issues with the relays) takes ages to fire and requires the accelerator pedal to be pumped or held down to catch the ignition. install 1-6 fuse all 12 fired!....turn off, and try to restart 6 cylinders bank 7-12 non fired. any suggestions, its obviously not a "terminal fail" on any one item. car ran perfectly for a 40 mile motorway run just over 4 weeks ago. (lucky break on start up i think....i was due some good fortune) is this a fuel pump, fuel filter, injection rail?....suggestions welcome on test procedures to narrow down the problem....... not CAT Thermocouple, not CAT ECU, not Motronic ECU, not Relays, not Fuses, not Battery..... thanks in advance for wise words and guidance....in advance "take to the dealer.....is the obvious answer....but i am sure most on here make that step once all avenues and miracles have been exhausted....otherwise whats the fun in having a Ferrari, the pain of ownership issues make the drive far more rewarding! i repeat that every night just to fool myself!
Can you get an OBD reader on it and see what codes it's throwing? Sounds like it's going into limp home mode, and something's still not right on 7-12
hi obd code reader will not recognise the 456 protocol....so no joy there! running out of options other than dealer!.... definately a problem on the LH bank... removed the LH Injection relay and tried to jump the signal...no click on relays further down the supply chain as there is with the RH Injection relay. LH and RH Fuel pump work fine. Remove the RH fuel pump fuse and the LH bank fires eventually....replace RH fuel pump and voila 12 cylinders. turn off engine and restart LH Bank down....forgot to put a multimeter on the injectors...so all pointing to electrical issue somewhere further down the fuel chain on the LH Bank - after the pump, disconnected feed ro fuel rail, jumped pump relay on LH fuel delivered. Need to check for spark on LH Bank and voltage to injectors when bank not operative... any ideas?....anyone?
MAY BE A DUMB QUESTION BUT HAVE YOU CHECKED THE TPMS VOLTS FROM LEFT TO RIGHT BANK?? TOLORENCE IS .70V FROM LEFT TO RIGHT DONE AT 3 DIFFERENT PEDAL POSITIONS.
hi thanks for the info... not a dumb question... I am not that familiar with testing vehicles, finding my way in the dark and learning on the way...and this is a whole new lesson! where would i test for those conditions? apologies, but if you have time and could give me a 101 on testing those parameters, i would be most grateful. thanks in advance
Hi Nigel, This problem is most perplexing isn't it? I don't fully understand what you've done here ".....removed the LH Injection relay and tried to jump the signal...no click on relays further down the supply chain as there is with the RH Injection relay......" but it sounds quite a conclusive test and worthy of further investigation. Is it possible to put a fuel pressure gauge on each rail (or one at a time) and observe what is happening while running and after shut-down? Is it possible that one side appears to be working fine (initially) but fails to maintain the correct pressure over a period of time? What you say about disabling the RHS and the resultant success on the LHS is intriguing. What set of circumstances can possibly allow this to happen? Do the two fuel pumps share the same earth? Is it possible that it's bad and one pump can be sustained but not two? Is it at all possible to switch over the fuel supply lines from side to side (with additional pipe) to see does the problem switch to RHS which (I think) would prove whether or not the problem is a fuel supply issue? Just a few ideas that occur to me from reading your recent post. Hope something maybe causes a "eureka" moment!
