Hi Muzza,
Following up on previous info:
ecu-fuel-system-eec-f21/anyone-here-no-how-to-make-ef-ford-falcon-diagnostic-unit-t31656-570.html[i]
[quote]OK, that clarifies.
The engine variant is irrelevant. Does not matter of it is XF or EL or AU of FG.
WRT diagnostics, it is the ECU that is running it that is key.
The connector you pictured is the one used in EB to EL.
The manifold is EA which used CFI (with two injectors in a carby like thing).
However, it is clearly MPFI as there is an injector per cylinder.

Steps forward....
1. Have a look at the ECU.
It will have a label on it and will say EECIV (EB, ED, EL) or EECV (EF, AU).
There will be four large printed letters on it.
Need those to confirm which ECU it is, but, if it has coil packs that it is either EF or AU.

2. Once the variant of the ECU can be confirmed, we will know which connector it should have.

3. Once the ECU and connector are clarified, we will know how to trouble shoot.
e.g. if it is an EF ECU then the connector is correct. If the commercial scan tool did not work then you have, most likely, a wiring issue.
e.g. if it is an AU ECU then that connector is incorrect and no scan tool would work.

Finally....
Could you please open a new thread on your car and its issues please.... do not hijack this one.
Send me a link to the new thread.


Info as requested:Current ECU = eecv 4DBF
Spare ECU = eecv 4DCF (both dis[play same problems i.e cant read codes)
Connector (see attached) has had some pins removed:
P= present
v=vacant
top row looking at the front of the connector left to right: pvv vpvvv vvp
bottom row: pvvvv vpnp

 

 

Attachments:

IMG_1402.JPG [ 74.65 KiB | Viewed 408 times ]

Thanks for the new thread.

4DBF is EF Falcon - 4.0 Auto - 5/95 to 10/95 (3.08 axle)
4DCF is EF Falcon - 4.0 Auto -12/94 to 8/95 (3.23 axle)

So both are fine in your application. The axle ratio part would affect transmission shift points.

There are around 30 different ECUs for the EF and aside from the axle variants, Ford just kept tweaking them over the years.

Although not impossible, it is highly unlikely that you have two crook ECUs with respect to the diags output.
So your issue is, most likely, wiring.
The Diag connector wiring:-
top row looking at the front of the connector left to right: pvv vpvvv vvp
bottom row: pvvvv vpnp

Bottom row looking at the front of the connector left to right (pvvvv vpnp) pin One is at the left and pin Nine is at the right end.
Top row looking at the front of the connector left to right (pvv vpvvv vvp) pin Ten is at the left and pin Twenty is at the right end.

The engine diag wiring is to Pins 1, 10, 14.
Pin 9 is 12v.

You have the correct pins there.

Check:-
1. There should be 12v between pin 9 and chassis (ign on).
2. There should be 12v between pin 9 and pin 1 (ign on).
3. Pin 1 on the connector should measure very low ohms to pin 91 on the ECU
4. Pin 10 on the connector should only go to pin 48 on the ECU (white/red wire)
5. Pin 14 on the connector should only go to pin 17 on the ECU (white/black wire)

Let me know how it goes.

Hi Muzza, some interesting results based on the info re wiring checks as suggested:


1. There should be 12v between pin 9 and chassis (ign on).
2. There should be 12v between pin 9 and pin 1 (ign on).
3. Pin 1 on the connector should measure very low ohms to pin 91 on the ECU
4. Pin 10 on the connector should only go to pin 48 on the ECU (white/red wire)
5. Pin 14 on the connector should only go to pin 17 on the ECU (white/black wire)

1. all good
2. all good
3. all good (8 ohms)
4. no connection to pin 48 at all (no pin/wire in 48)
5. no continuity between pins 14 & 17 (ECU) however there is red/yellow wire in pin 17.

But....
Pin 10 goes to pin 66 (white/red, as in your comments)
pin 14 goes to pin 55 (white black, as in your comments)

Works in progress....

Firstly and apology. I misread the wiring diagrams and gave incorrect info.
Discovered this whilst reviewing your response.... I am embarrassed.

What the wiring should be:-
1. There should be 12v between Diag pin 9 and chassis (ign on).
2. There should be 12v between Diag pin 9 and Diag pin 1 (ign on).
3. Diag Pin 1 on the connector should measure very low ohms to pin 91 on the ECU
4. Diag Pin 10 on the connector should only go to pin 66 on the ECU (white/red wire)
5. Diag Pin 14 on the connector should only go to pin 2 on the ECU (white/black wire)

You advised that:-
Diag Pin 1 is correct
Diag Pin 10 goes to ECU pin 66 - this is actually correct.
But....
Diag Pin 14 goes to ECU pin 55 - this is incorrect
ECU pin 55 (wht/blk) is a 12v feed into the ECU and is on the same circuit that appears on pin 9 of the Diag connector.
This is your issue and why diags do not work.
You need to get Diag pin 14 to ECU pin 2. You should see a wht/blk wire at pin 2. It should be a direct wire between the Diag pin 14 to ECU pin 2.
ECU pin 2 (Diag connector pin 14) is the diag codes output signal wire.
Make sure there is no 12v on Diag pin 14. If ECU pin 2 is connected to 12v it will burn out the output device in the ECU.

I have double checked the wiring this time and is correct info this time ... again, apologies for the error.

Ok a little more testing & head scratching has revealed that diag pin 14 going to ecu pin 55 has 12v ign on/off.
There is continuity between the connection from ecu pin 2 to diag connector pin 9 (8 ohms) and diag pin 9 has 12v with ign on.
So it appears that diag pins 9 & 14 have been reversed? (same colour white/black) and because ecu pin 2 has 12v you think that damage has been done?

Yes, it appears that it is a transposition due to the same colour wires.
Easy mistake to make.

The 12v at ECU pin 55 is continuous voltage and is the "keep alive" memory voltage.
It also powers the fuel pump via the EFI systems Power relay and Fuel Pump relay.
That circuit goes to Dig pin 9 and powers the diagnostic test unit when it is plugged in.

The Diag output (STO) has a pull up resistor which would limit the current that can be drawn out of ECU pin 2.... so trying to power the diag tester should not cause any issues.

The STO signal is a ground switched by a transistor.
If a full 12v was connected to pin 2 whilst the diag codes were being sent it would burn that transistor.

In your case, as long as it is a simple transposition error at the diag connector and the wire from ECU pin 2 currently only goes to Dig pin 9, then there should have been no damage.

Yes, looks like if you "un-reverse" the two white/black wires all should then be correct.

Send me your email address via a PM and I'll send you a copy of the EFI system wiring (PDF format).

Ok ,so wires un-reversed as mentioned,still unable to download any codes,about to swap ECU with spare.
Just need to clarify which procedure/codes should I be using: EF or AU
the engine is from a 98 AU1 with modified intake manifold as previuosly mentioned, coil pack,crank & cam sensors etc..
The ECU is from an EF with a TI performance chip in the J3 socket.
So which model do I set the scan tool for EF or AU1

EF.