Technical Quick CAN overview please '56 plate 1.2

[Avocet]

Hi all. Would someone be able to give me a quick CAN system overview please? First of all, would an early 2007 car have a CAN system? I've a feeling it might, looking at some of the wiring. I have two faults that I haven't been able to trace as yet.

1. The stereo lights (just the backlights behind the buttons) won't go out. You can take the key out, lock the car and leave it all night - the lights stay on! They flicker a bit when I turn the ignition off though.

2. Secondly the rear fog light doesn't work. I only get about 6 Volts at the bulb holder. I've cleaned all the earths I can find and chased the wires to the inside of the car (where they are still only showing 6V). I've pulled the fuse box out and cleaned all the contacts with switch cleaner (they all looked good and shiny anyway), so now I'm a bit stumped.

If it does have a CAN system, would anybody be able to tell me where the CAN controller is? Doing a search has pulled up terms like "BCM". Does that stand for "Body Control Module"? That might be what I'm calling the CAN controller. Also, the term "proxy alignment" cropped up a few times. Is this something that can be done as a DIY proposition or do I need something like Multiecuscan?

 

[g8rpi]

Hi all. Would someone be able to give me a quick CAN system overview please? First of all, would an early 2007 car have a CAN system? I've a feeling it might, looking at some of the wiring. I have two faults that I haven't been able to trace as yet.

1. The stereo lights (just the backlights behind the buttons) won't go out. You can take the key out, lock the car and leave it all night - the lights stay on! They flicker a bit when I turn the ignition off though.

2. Secondly the rear fog light doesn't work. I only get about 6 Volts at the bulb holder. I've cleaned all the earths I can find and chased the wires to the inside of the car (where they are still only showing 6V). I've pulled the fuse box out and cleaned all the contacts with switch cleaner (they all looked good and shiny anyway), so now I'm a bit stumped.

If it does have a CAN system, would anybody be able to tell me where the CAN controller is? Doing a search has pulled up terms like "BCM". Does that stand for "Body Control Module"? That might be what I'm calling the CAN controller. Also, the term "proxy alignment" cropped up a few times. Is this something that can be done as a DIY proposition or do I need something like Multiecuscan?

Ye,s your car has CAN. There are several "nodes" on the CAN bus, the Body Control Module is a CAN node and may be causing some of your faults.
You need Multiecuscan software on a laptop and an interface to carry out a proxi alignment, but it is a DIY job. For anything other than basic CAN information on a GP you will have to pay the registration fee for Multiecuscan (€50) but it's well worth it. An ELM 327 interface like ebay item
271275445368 will work. Get an interface and try the free version of Multiecuscan to make sure it works OK before paying the registration fee.

Robert G8RPI.

What engine does your car have?

 

[Avocet]

Fantastic! Thanks Robert.

It's a 1.2 (8 valve).

 

[PuntoHowTo]

The radio uses the canBus to know when the car ignition is on or off.

If the radio switches off when you switch off the ignition but the radio lights stay on then it's quite likely a fault internally in the radio.

The fog light is fed by a relay, I'd
Look at the voltages at this relay could be as simple as a new relay, or possibly a shorted
Wire somewhere but is again unlikely to be a CAN issue

 

[Avocet]

Thanks for that. This is the second radio the car has had and it came out of a scrapper. The first one just stopped working. It out up,took and ejected CDs, searched and found stations, but no sound came out! This second one works (and yes, it switches on and off in all respects other than the button backlights).

Interesting about the relay. Is it in the main fuse box by the battery?