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View Full Version : CAN error: Comm Area Network.



yy101
05-22-2007, 03:13 AM
Okay this is supposedly whats wrong with my DME, its throwing up this error code on the Car-Man Scanner my indy has.

Will check all fuses and wiring...anyone else have any idea what else it might be?

pingu
05-22-2007, 03:58 AM
The CAN bus is a serial bus (a bit like RS232 but electrically a bit more electrically rugged so it doesn't get upset by all the other electrical stuff - like alternators and spark coils - going on under the bonnet).

If you're getting a CAN error then it might simply be a case of a defective wire to whatever module (auto controller?) the DME is attempting to communicate with. Can you check out the wiring? If I remember correctly, the CAN bus is a differential bus (i.e. two wires; it's not a case of one being Tx and one Rx, they're both used together - but only one module (e.g. the DME) can talk at a time).

The CAN bus was specifically designed to be used in an automotive environment so I'd be surprised if hot plugging your DME had killed the CAN bus interface.

yy101
05-27-2007, 02:46 PM
The CAN bus is a serial bus (a bit like RS232 but electrically a bit more electrically rugged so it doesn't get upset by all the other electrical stuff - like alternators and spark coils - going on under the bonnet).

If you're getting a CAN error then it might simply be a case of a defective wire to whatever module (auto controller?) the DME is attempting to communicate with. Can you check out the wiring? If I remember correctly, the CAN bus is a differential bus (i.e. two wires; it's not a case of one being Tx and one Rx, they're both used together - but only one module (e.g. the DME) can talk at a time).

The CAN bus was specifically designed to be used in an automotive environment so I'd be surprised if hot plugging your DME had killed the CAN bus interface.

Hey mate I had a look trying to find the defective wiring, but not sure where I should be looking. Where is the CAN bus located?

pingu
05-29-2007, 05:47 AM
As far as I know (I'm guessing somewhat here), the CAN bus is part of the wiring loom.

You can probably work out which pins on your DME go to the CAN bus by looking at a wiring diagram. Then maybe check to make sure the two CAN bus wires aren't shorted to chassis.

Good luck!

Ross
05-29-2007, 08:33 AM
Most of the electrical problems I encounter are a failure of a mechanical connection rather than the failure of an electronic component. Swiches, relays, corroded or disturbed connections outnumber electronic component failures in my experience..
Since your trouble began after disturbing things to swap a component I'd have a real good look at all the connections again.
My $.02