Another Computer Display Question

[obews]

Firstly - HappyNew Year everyone !
My problem is with the wifes 07 Vectra SRi trip computer - Safe seems to keep coming up and when it's put to miles to go with fuel etc it seems to be erratic - would this be the display itself - is this the computer and do I just replace the display unit or does the info come from another source ?

[Robsey]

Hmm - which head unit and display?

The display sounds like it is either faulty or has a loose connection.
The Display is the device that receives the information.

The ECM - Engine module operates on the high Speed CAN.
The CIM - Collumn Integrated Module acts as the gateway between high speed CAN and low speed CAN.
This information is then fed along the low speed CAN network via the IPC (Instrument Panel), then the BCM (Body Control Module and then to the DIS (Display).

As regards your issue...

Firstly - I would disconnect the car battery for half an hour or so.
When you reconnect the battery, it will force all the modules to do a "soft" reboot.
In 90% of cases, this will sort the problem... an electronic glitch.

Do NOT disconnect the battery within 5 minutes of the engine running, the ignition being.
Again like computers, modules need to power down properly and this takes approx 5 minutes to do.

If this does not sort the issue, then check the fuses at the end of the dash panel...
You should check fuses
1, 7, 9, 10, 12, 17, and 26.
These fuses affect / supply the modules listed above.

If the fuses are okay, and the problem persists, then it is most likely a faulty display... not cheap to replace!!
And a pig to program if you do not know the procedure and all the faffing that it involves.

[obews]

Thanks for all the info - once the wind and rain have died down I will try all as above ! Cheers.

[Robsey]

when it's put to miles to go with fuel etc it seems to be erratic

If this is the basic fuel consumption and range page, then the consumption figure will jump around. That is normal.

The fuel figure is the instantaneous consumption... so it will go down if you accelerate,
and go up if you are gentler on the accelerator...
if you are slowing down, it is normal for this to go up to 999.9 miles per gallon.

So - it is just the rate at which you are using fuel at that instant...

When parked in neutral with your foot off the pedal, it should say 0.1 gallons per hour.

it will change to miles per gallon when you go above approx 8 mph.

Apologies if this is not what you meant...
You will only get a steady consumption figure if you select "average" consumption.

So regarding the "SAFE" message.

If this has only just started happening and you have had the car a while, then it sounds like the power supply, an electronic glitch or a faulty display.. as per my previous post.

If you have only just got the car, and it does this every time, you turn on the ignition, then the display and/or head-unit is in delivery mode, and needs to be married up / paired properly.

I am assuming that the safe message pops up every 5 seconds or so, because if the units were paired but not to each other, then the "SAFE" message never goes away and you would not be able to see the consumption figures.

[obews]

Thanks once again. I have been out this morning and disconnected the battery for well over an hour and then reconnected it - no "SAFE" sign at all and the display seems all ok now - will keep an eye on it after her indoors has been back to work in it !
Will let you know.

[Robsey]

Thanks - looks promising.

The problem is - in my very simple terms...
There are many modules all "talking" to each other on the same network.
This is a bit like me or you having a chat across a pub table when there are other people talking just as loud at the same time.
You try to concentrate on the other person to whom you're talking, but sometimes things get mis-heard or not heard at all.
(I am told it is a bloke thing - lol )

The CAN system tries to prioritise messages, but occasionally some messages do net get through or get confused, due to the presence of more important messages on the same network.