456 wont start. Need help troubleshooting.

Omar said… What was the solution to the problem of not having a pulse signal in the injectors and coils? I have the same problem in a 456 GTA.

@Osmar Araujo Neither the original poster nor @furrariTO have been on FerrariChat for a long time and neither have bothered to provide a follow up.

Does your Check Engine light come on prior to start? Do your ECUs have test buttons? Do you have an aftermarket immobiliser? What faultfinding steps have you tried already?

 

eu think the problem is in the imoomobilizer that went into panic mode

 

EU active the alarm and the led flashes, then I deactivate the alan abd the led turns off, when i turn on the ignition it flashes and then stays on continuously, could this be a sign that the immobilizer is activated ?

 

quis dizer alarme e não alan...

 

I ran the scanner and it keeps showing the error code P1625( ECU power supply)

 

A luz de verificação acende , pisca uma vez e fica acesa direto esta correto ? Não .. minhas ecus nao tem botões de teste, nao tenho imobilazador de reposição , ja escaniei e aparece a falha de sem alimentação da ecu p1625

 

Caso queira entrar em contato sou do Brasil ,55 11963267803

 

outra coisa , quando eu desligo o fio amarelo que vai com o resi no pino 86 que tem o resistor de 120ohm ao cortar o fio o motor pega e morre , aí notei que somente o lado esquerdo funciona, apenas uma banca de bicos e bobinas 7-12

 

só pega com o fio desligado apenas por 3 partidas depois não funciona mais, aí se eu ligar o fio amarelo ele fara igual ,somente uma bancada funciona e corta em seguida

 

Já testei os sensores de mavelas, bombas de combustível,troquei o sensor de fase. Verifiquei toda caixa de fusiveis

 

Sensor de manivelas

 

Sorry, I don't speak Portuguese. Guido (from Brazil) makes circuit boards. I'm not sure if he can help you with diagnostics.

Do you have a 456 with a 5.2 engine management system (which includes a factory-fitted immobiliser)?

All I know is that a solid red LED indicates some kind of fault. However, if your engine is cranking, it's not affecting immobiliser's ability to unlock the engine ECUs. Your immobiliser siren battery might be faulty.

Osmar said: I have already tested the crankshaft sensors, fuel pumps, and changed the phase sensor. I checked the entire fuse box.

Are you telling us that the crank sensor fixed your issue (even though you said you tested it)?

 

Osmar, esse painel de fusíveis não parece bom! E uma vez que seu painel de fusíveis esteja desmontado, ele não poderá mais ser consertado.

 

If he has any available, @theunissenguido fuseboards are so much better and well built, it's just time for an upgrade. It's such an easy upgrade. How are your plugs into the fuse board?

Also you mentioned crank sensors... was that the problem? Or your next area to look into?

 

I mentioned the crank sensors, that's where I started testing but it didn't solve my problem

 

Mencionei os sensores de manivela, foi aí que comecei a testar, mas não resolveu meu problema

 

The problem came after disconnecting the immobilizer for testing after plugging in the engine it didn't work anymore, it only works if I disconnect pin 86 (which is a yellow wire with a 120ohm resistor) then it starts and then turns off it only works on 6 cylinders (left bank)

 

How long does the left bank run? A few seconds?

Why did you disconnect pin 86? That seems rather random.

Pin 86 is part of the databus circuit which connects the two Motronic ECUs. The resistor, of course, is for impedance matching. The databus may have things like coolant temperature and perhaps even immobiliser data running on it (?).

At the moment, I don't know if the issue is the databus wiring or the data on that wiring that is missing/corrupted.

Did you do resistance checks on the databus wires? RH ECU pin 86 to LH ECU pin 86? RH ECU pin 85 to LH ECU pin 85 (and the resistance between pins 86 and 85)? Unfortunately, it's quite a complex circuit, at least on the 456M. The 456M circuit involves the ABS ECU and the automatic gearbox on the M GTA.

If I recall correctly, the inline connector between the two ECUs is hard to get to. It's hidden at the back of the engine. During engine work, sometimes these are not reconnected.

 

Olá, já testei a continuidade do chicote e medi a resistência entre cada ECU. Soltei o chicote que está preso à caixa de câmbio para ter acesso. Ele acaba sendo conectado ao chicote de um dos sensores de rotação. Não há mau contato ou algo parecido, apenas mais mistérios.

 

Did you recheck the pins on the Immobilizer ECU pins after refitment. Maybe you bent a pin?

Did you say the engine was cranking, but not running. If so, your Immobiliser should be ok. Your immobiliser controls cranking and fuel injection.

I don't really understand your comment about the rotation sensor harness.[/QUOTE]

 

[/QUOTE]
O fio 86 sai do módulo do lado direito passa pelo motor e ali nos bicos ele chega a um conector que leva ao outro módulo do lado esquerdo , que depois volta novamente por trás do motor chegando até um dos sensores de rotação

 

O fio 86 sai do módulo do lado direito passa pelo motor e ali nos bicos ele chega a um conector que leva ao outro módulo do lado esquerdo , que depois volta novamente por trás do motor chegando até um dos sensores de rotação[/QUOTE]
Sim verifiquei milhões de vezes os conectores estão todos o, do imobilizador , ele comanda , sinal do motor de partida e bloqueia o módulo para não ter pulso nos bicos e bobinas então não tem faísca nem combustível para os cilindros .

 

Do you have any wiring diagrams for your car? I don't have a diagram for the 456 (5.2), only for the 456M. I think there may be some wiring differences. Here is the diagram for the 456M right bank (cyl 1~6):

https://www.dropbox.com/t/lk6ju3nz6IhjPyVe

Here is a graphic of the wiring harnesses and connectors:

Image Unavailable, Please Login

At the moment, there is somewhat of a language barrier and a lack of system knowledge on my side. You mentioned RH Motronic pin 86 which is attached to connector 10L/31L in the graphic. Can you clarify what happens when you remove wire 86 and what happens when you don't remove wire 86? Does the engine crank/not crank? Do the injectors fire (momentarily) or not at all in either configuration?

In your wiring checks, have you confirmed that connector 10L/31L is actually connected? Does disconnecting 10L/31L produce the same effect as removing wire 86?

Maybe Guido @theunissenguido can provide a better translation than Google?

 

Olá, ao desconectar o fio do pino 86, o carro funciona, mas depois desliga. Foi aí que testei e, ao dar a partida, apenas um lado do motor tem pulso e faísca, mas o motor só funciona por alguns segundos.

 

I'm trying to determine whether the issue is the immobiliser or something else. Normally when you have fuel and spark, the immobiliser and crank sensor are ok. However, pulling the wire on pin 86 may be temporarily fooling the circuits in the Left ECU to operate without getting an unlock signal from the RH ECU (Usually the RH ECU talks to the Immobiliser ECU and the RH ECU sends a signal to the LH ECU on the inter-ECU CAN Bus).

I'm wondering if there is a short to ground on the pin 86 wire or the 85 wire which is preventing running. Normally, on other Ferraris, if the CAN Bus link between the R & L ECUs is disconnected or compromised, the engine won't run (I'm not sure about the 456 5.2). I know you have done wiring checks, but have you done a check for a" short to ground" on pins 86 and 85?