Alfa 147 2litre TS 2004 - Siemens Airbag error

[goforit1]

Need help please. airbag light on can't clear error code 1A which according to multiecuscan refers to the warning light circuit. I've cleaned and silicon greased both connectors on airbag ECU, seat connectors, steering wheel connector and connector to dashboard instrumentation. error code will not clear. Car has not been crashed and no airbags deployed. I don't know why I can't clear this error.

[Alfaeddy]

Hello Goforit1


What is displayed in the error description from the Multiecuscan?
According to my records, the

A1 error is an error in the airbag warning light

You should check the wiring to the warning light check
from the controller to the warning lamp is probably an orange cable
down.

Have you checked the fuses?

Greetings Eddy

[goforit1]

Thanks Eddy,

Yes error 1A description is as per your record - an error in the warning light circuit. No I haven't checked the fuses but will do so tomorrow. I will also look for and check orange wire which I assume you mean runs from the control unit to the connector plug at the back of the instrument panel?

It would be so useful to have a colour coded wiring diagram!

[Alfaeddy]

Hello goforit1

Unfortunately I have no cable run of your Alfa 147
Have the cable only taken from the Alfa 156 also has a My97 Airbag
and there is the diagnostic port orange

But the Alfa 147 is also a My airbag 99 by Siemens was used, and I do not know what you have

Greetings Eddy

[goforit1]

TerminalContact.jpg (4.9 KiB) Viewed 2467 times

Alfaeddy, many thanks for your contribution. Here is the update giving the resolution:

after spending 4 hours with a brilliant auto electrical specialist and failing, I resorted to disecting the connector to the back of the instrument panel I've finally tracked the fault! So ..... simple with hindsight! it was in fact 2 of the female connector terminals. These connectors are widely used throughout the auto industry and I bet they keep many people in work! They are part of TE connectivity's quadlock range. Now for the interesting part.... the female terminals in the loom connector are of a rectangular cross- section with slightly bent clips at the entry point which after a few years of vibration loosen up ensuring the round male pins don't make contact.

I tried individual female terminals into the pins on the instrument panel and for 2 of them, it was like a "sausage in a bucket' fit!

Moving the connector wont help as the locking feature ensures security against mechanical movement. This is bad bad bad, because if you test the circuits with a multimeter by inserting probes into the front of the connector, you will find no fault/no break in continuity. I'm sure I'm not the only one to have discovered this.