Technical Multiple coil and injector error codes and will not start.

[hoopertjam]

Hello to all in the Fiat forum. I've attached a print out from MultiECU that specifies errors to all the injectors and coils on all cylinders on my 1.2l 8v petrol my2008 Fiat 500. I'm guessing that there is either a wiring or ECU fault. I do possess both multiECU and a copy of the Fiat 500 examiner CDrom. Any advice about causes or diagnostic procedure would be greatly appreciated.

 

[hoopertjam]

I've been continuing my uneducated search through potential causes for the above problem and I've noticed that the same fuse is responsible for both the coils and injectors (F22). So my guess is, the problem us with the wiring within this circuit or maybe the fuse itself. I will check the fuse in the morning. I'm still eager for any diagnostic advice regarding the error codes in the attachment in my previous post.

 

[varesecrazy]

Hi.
I would do the re.routed earth cable 1st.

As the U code is the bigger clue to me.

 

[wardpaa]

There is a previous thread on this where I uploaded the circuit diagram showing F22 and the earth locations.

https://www.fiatforum.com/500/464043-ignition-failure-multiple-cylinders.html?p=4367711

As previously mentioned in the thread, the earthing would be the first place to check.

 

[hoopertjam]

Thank you for both of those replies. I have found the earth in question underneath the air filter. It looks fine, are there any measureable voltages on that circuit that I could check with a multimeter?

 

[Goudrons]

I wonder if the coils and injectors share the same earth and there's a problem with the wiring loom from the ECU?

The Panda Active has a similar issue with a dodgy wire in the loom that causes coil and injector issues.
The wire in question is very near to the connector to the ECU and the fault can be manipulated with the wire.

This one shows the issue and relates to coil, but it has also shown as injector problems as I believe the wire splits with a Y junction further along the loom.
https://www.fiatforum.com/panda/420817-injector-problem-code-p0202-cyl-2-injector-2.html?p=4119624

If you knew which pin on the connector is was, you could run some continuity tests at the coil and injector ends.

 

[wardpaa]

In the attached, A030 is the 6 way connector to the coil pack with pin 1 being +12V and pin 6 being ground.
The injectors do not share the same common ground as they are grounded by the ECU individually when activated, but they do work off the same +12V fuse F22; Pin 1 of A030 and Pin 3 of D081.
So failure of both would probably mean tracing the +12V feed through the loom to F22.

 

[hoopertjam]

Thank you to everyone for the helpful replies. Update to the situation. The car just started this morning. So I've checked, cleaned and lubricated all earths, fuses and relay connections. I've also tried to make the fuse box enclosure in the engine bay more secure as that was particularly loose in every way. Fingers crossed that is the end of it. I shall return here if that is not the case.

 

[varesecrazy]

Good news.

(FYI: the earth cable can fail internally..
So replacing it .. or running a secondary cable.. is advisable)

Do let us know how it goes.

Charlie

 

[jpsmcginn]

In the attached, A030 is the 6 way connector to the coil pack with pin 1 being +12V and pin 6 being ground.
The injectors do not share the same common ground as they are grounded by the ECU individually when activated, but they do work off the same +12V fuse F22; Pin 1 of A030 and Pin 3 of D081.
So failure of both would probably mean tracing the +12V feed through the loom to F22.

Hi there,
I am installing a secondhand 30k Ford KA engine in my old Fiat 500 312 1.2 8V. I've noticed the Ford fuel injectors wiring loom looks the same as the old FIAT one but has a different product code stamped on the loom label. The injector loom had been fitted with the connector sited on the left (nearest the cambelt) rather than the right nearest the main loom at the thermostat (where I had expected it to be). I removed the fuel rail, cleaned the injectors when in there and refitted with the injector loom connector at the thermostat and connected it up to the main loom. However, I am not 100% sure if I have the injector loom connectors on the correct injectors - is there any way to confirm?

John

 

[jpsmcginn]

Hi there,
I am installing a secondhand 30k Ford KA engine in my old Fiat 500 312 1.2 8V. I've noticed the Ford fuel injectors wiring loom looks the same as the old FIAT one but has a different product code stamped on the loom label. The injector loom had been fitted with the connector sited on the left (nearest the cambelt) rather than the right nearest the main loom at the thermostat (where I had expected it to be). I removed the fuel rail, cleaned the injectors when in there and refitted with the injector loom connector at the thermostat and connected it up to the main loom. However, I am not 100% sure if I have the injector loom connectors on the correct injectors - is there any way to confirm?

Below is the original FIAT injector loom in the orientation it would be in the engine bay (facing the exhaust manifold). I notice each injector has a common yellow/grey wire and injector #1 has an additional blue/black wire, injector #2 has an additional grey/black wire, injector #3 brown/black and injector #4 red/black.

Loom code: AG 0077425 .B
Date of Manufacture: 16/10/08

 

[jpsmcginn]

Loom code: AG 0077425 .B
Date of Manufacture: 16/10/08

View attachment 454728

Assuming the bottom is pin #1: red/black, pin #2: brown/black, pin #3: common yellow/grey, pin #4: grey/black, pin #5: blue/black.
This doesn't match the wiring diagram above (I assume I have an older loom) so will check the more recent Ford Ka loom this evening and report back.

 

[jpsmcginn]

View attachment 454729

Assuming the bottom is pin #1: red/black, pin #2: brown/black, pin #3: common yellow/grey, pin #4: grey/black, pin #5: blue/black.
This doesn't match the wiring diagram above (I assume I have an older loom) so will check the more recent Ford Ka loom this evening and report back.

As suspected, the newer wiring loom is physically the same but different wiring colours. The wiring loom code is also different - AG 8114312 .C
I'm going to plug it into the main ECU loom and hope for the best (well I will check pin #3 is common to all injectors first!).
Does anyone know if the Fiat 500 312 needs the ECU programmed with the serial numbers of each injector, by port number?

 

[jpsmcginn]

As suspected, the newer wiring loom is physically the same but different wiring colours. The wiring loom code is also different - AG 8114312 .C
I'm going to plug it into the main ECU loom and hope for the best (well I will check pin #3 is common to all injectors first!).
Does anyone know if the Fiat 500 312 needs the ECU programmed with the serial numbers of each injector, by port number?

View attachment 454847

OK, don't do this! This wiring loom is for a later model and does indeed have the connector on the alternator side of the engine bay. I've ordered a new wiring loom for my 2007+ model and will swap out when it arrives!