430 No communication with ABS & Airbag

One of these days, someone is going to create a scanner which produces messages people can understand. Does ABSENT mean the fault is in memory, but not currently active?

Guilherme, what does ATT and MEM mean in Portuguese?

1. U1706 No communication with NFR (brake module)
2. U1700 No communication with NBC (body control module) ... The message is not shown on the TEXA scan... The F430 doesn't have an NBC.

If E11 is the OBD2 port on your wiring diagram, then what is X1? In my Scuderia diagrams, nothing appears to be attached to pin 2 of the OBD2 port. Shouldn't you be looking at pin 16 on the OBD2 port for the K line signal?

 

Thanks. The Scud diagram was confusing me:

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I have the CAN C Bus H & L lines going to pins 6 & 14 of the OBD2 port (and I saw these pins used in the Texa wiring diagram). The K line goes to pin 12 of the OBD2 port on the Scud. There is no Bus A (as mentioned on the Launch readout).

Also, I mean to say pin 6 on E11, not 16 in my previous message, but disregard that anyway.

For what it is worth, on the Scud, pin 11 goes to pin 12 of the OBD port.

 

As there is nothing on pin 2 on your car, perhaps the Scud diagram is correct for your car:

Pin 12 of the Scud OBD port, is attached to:
Pin 6 (plug B) of the Instrument Panel
Pin 11 of the Brake ECU
Pin 18 (plug B) of the Window ECU

 

It kind of makes sense. The ABS ECU is responsible for putting on the light (for at least some issues). ABS dead, so no light... but can the Instrument Panel also put on the light when there is no comms from the ABS? If so, perhaps there is a time delay or some other logic for this?

It seems that numerous computers are reporting the failure.... Instrument panel, Suspension ECU, RH Motronics, etc, so it's either the bus wiring or the ECU.

 

I know I am coming here late but you had a lot of codes that are absent and we're most likely caused by low voltage (most likely on cranking) .. have you checked your voltage when cranking to see if that explains the issue ..if not you may have a ground issue for all thoae errors to show up

Also know once one control unit goes bad on a bus usually it causes others to report errors


Ignore the first skyhook error since it most likely was set by health check

To see if codes exist ..go into the individual module ..clear code ..drive and then see if it came back by again only going to that specific module

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Ok - i think the ABS/CST light may be coming on due to the p1781 .. low pressure in f1 circuit / Ediff circuit
If you want we can diag together with some basic timings etc and see it we can fix the issue
In terms of not getting to the ABS system - i can't remember if the launch can read it .. I only remember than it has problems resetting airbag
I sent you a PM to discuss this issue .. I may be off but I think 15 mins on the phone with the car we may figure it out

 

There’s a limited number of devices on pin 12 (at least on the Scud). Do you think other devices on other lines would be affected?

 

Yes

As mentioned above ..when item on bus fails the bus doesn't work like the bmw

I believe it is the ediff module/subsystem (solenoid /sensor) that may be causing the issue or something in F1 system tricking down ..speak to later



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My plans changed if you like to call me now

 

The wiring is broken up into dozens of different OEM diagrams and some details are missing. However, I've provided links to my custom diagrams where available.

On the Scud....

I couldn't find an Alarm diagram which shows the OBD2 pin (but comes from pin 2 plug A on the ECU).
Airbag is on pin OBD2 pin 12 (and comes from pin 3 of plug A on the ECU). https://www.dropbox.com/t/swtGnhCPE8z8beuo
Instrument Panel is on OBD2 pin 12 (and comes from pin 6 of plug B on the panel). See Airbag diagram.
The Braking diagram for the Scud is different from the standard F430 (different ECU pinout). Standard 430 diagram here thanks to @mike32 : https://www.dropbox.com/t/LO9X1zPIv4Ts48pB
I have a very blurry picture I found online of the Parking Sensors and that is on pin 12 (I can't clearly read the pin number on the Parking Sensor ECU, but it may be pin 12 on plug B). https://www.dropbox.com/t/giqjWGGo5pRpQyeJ
The Window ECU is on OBD2 pin 12 (and comes from pins 18 on plug B on the ECU... but different cars have different pin numbering... it may be on pin 13 (whichever has the white/red wire). https://www.dropbox.com/t/sgfIqsw9Ri6DK96F

Immobiliser is on OBD2 pin 3 (coming from pin 5 of plug B on the ECU).
F1 is not on OBD2 pin 12.
The other systems also seem to be on other OBD2 pins.

 

Ian

I am working offline with OP ..there is an issue with the F1 system and will fix that first .. i think the ABS/CST light is all related to that
SO lets hold off until we fix it .. may take a few days for parts

 

Seems I missed this diagram... It shows most of the pin 12 connections:

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As mentioned before, the ABS system has a different ECU on the Scud. Also, the Parking Sensors ECU is not shown. EM27 is the E-diff. in case you're not familiar with the symbol.

 

My theory here is OP is losing pressure fast ..maybe a bad accumulator based on first test .. then when the pressure gets low enough it sets off the cst light because the ediff is getting the pressure it needs

Let's fix the p1781 first and then see what's next

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Did you mean to say the ediff is not getting the pressure it needs?

Would the scanner show this (if it was working)?