Ford Fiesta Hacker's Guide - things not in the manual

**kevo888** · February 27th, 2011 11:48 PM

I assume that the computer must send a signal to the seatbelt fixture at a certain speed to check if the seatbelt is engaged in its slot.
Could this signal be "intercepted" and used to trip the dashboard lock button?
It would seem to me that as the computer has the ability to detect the speed of the car already, that would be the obvious mechanism to "hunt down" and be used to trigger the autolock.
That way, it wouldn't matter if you had a manual or auto transmission. I assume the seatbelt warning mechanism is available in all models.

**vivafoxpro** · February 28th, 2011 12:44 AM

Originally Posted by kevo888

I assume that the computer must send a signal to the seatbelt fixture at a certain speed to check if the seatbelt is engaged in its slot.
Could this signal be "intercepted" and used to trip the dashboard lock button?
It would seem to me that as the computer has the ability to detect the speed of the car already, that would be the obvious mechanism to "hunt down" and be used to trigger the autolock.
That way, it wouldn't matter if you had a manual or auto transmission. I assume the seatbelt warning mechanism is available in all models.

That is a very unique view on how we could surmise how the computer would know the status of the seatbelt slot. The computer sends out a voltage to the slot, then waits for it to return via the other wire.

My own guess is all of these "sensor" points have a fixed voltage always. When a switch is triggered, voltage is sent up the computer. The computer saves one step and just observes if any voltage is coming from the sensors.

This second method has very little electric consumption while cutting complexity in half. The computer not asking anymore, just "listening".

Wiring is also reduced since the first scenario would require 1 wire going towards the sensor plus 1 wire coming back. With 5 doors, seatbelt, bonnet and who knows how many other sensors (ABS has one also), this could really add up.

Second scenario would just have the positive line common to all and send up just 1 signal wire for each sensor.

**kevo888** · February 28th, 2011 01:05 AM

I think the only way to tell how it works is to open up the drivers side seatbelt slot. It may be simpler than we think. Maybe it has a microswitch in there already

I think we know who we want to volunteer....wink wink

**kevo888** · February 28th, 2011 03:49 PM

Just climbed under my driver seat to take some pics of the wiring going to the seatbelt slot.

There are 2 wires, Black and Red, going to seatbelt mechanism.

My assumption would be that the seatbelt slot has a microswitch that is closed when the seatbelt is in use, therefore completing the circuit of the Red and Black wires. The computer then checks this circuit at a certain speed.
If the circuit is not closed, the seatbelt warning will then sound. How we get that to trigger the autolock is one for the experts ie * Vivafoxpro

**kevo888** · February 28th, 2011 05:42 PM

Update:-
I connected my multimeter to the black and red wires to try and detect a current. (The square plastic connector box can be removed easily by grasping the box from the front, pressing in the buttons on the side, and sliding the box towards the footpedals).
Interestingly, I did not detect a current. I tried with the car, engine running, in D and P without handbrake.
The only way to test it fully would be to drive around with the multimeter connected to see if the current "spikes" when the seatbelt warning chime sounds (I don't have time to do this at the moment).
If it did, and the computer is only sending the current when it needs to check if the seatbelt is engaged, then we have a good signal to trip the autolock

**hausteam** · February 28th, 2011 06:35 PM

I tried something earlier. When I drive with the seatbelt extended but NOT LOCKED to the clip, I don't get the seatbelt warning. It's only when I release the seatbelt and it runs back in to the pillar that I start hearing the alarm. Can anyone confirm this?

**tidus1203** · February 28th, 2011 06:40 PM

Sige when I have the time I will try doing it too hausteam and I will try to confirm back here...

**river enchanter** · February 28th, 2011 09:11 PM

regarding the seatbelt chime/icon, once i have tried to connect the belt of the front passenger's to the lock of the driver's and voila! the chime stopped...i guess this is a different twist to hausteam's experiment

**pista_ni_jon** · February 28th, 2011 09:21 PM

Originally Posted by hausteam

I tried something earlier. When I drive with the seatbelt extended but NOT LOCKED to the clip, I don't get the seatbelt warning. It's only when I release the seatbelt and it runs back in to the pillar that I start hearing the alarm. Can anyone confirm this?

sir hausteam, this is not possible on my end. i've tried this long after i got the unit. ang naging solusyon ko sa ingay ay gamitin ang belt sa rear middle passenger. yun ang nakasaksak sa clip para hindi nako si-seatbelt lalo na kung around the village lang ang pinupuntahan ko.

**kevo888** · March 1st, 2011 12:00 AM

I just found this on a UK forum regarding disabling the seatbelt chime.

"Turn the ignition to position 2 and buckle and unbuckle drivers seatbelt 9 times. The light in the cluster will flash 3 times"

Source - http://www.fordownersclub.com/forums...howtopic=17854

Or just push another buckle in the slot, either rear belt or passenger.
Please don't turn this into a discussion on seatbelt wearing. I just posted this for anybody that is interested. I always wear my seatbelt, so don't need reminding, but I will leave the chime enabled anyway.