View Full Version : CAN bus sleeping?

05-11-2019, 09:48 PM
working on my 2004 Sprinter, I am reading an instruction saying, "allow the vehicle CAN bus to go to sleep." What does that mean and how do I do this?

05-11-2019, 10:22 PM
May I presume the procedure’s next step is “disconnect the battery”?

The various modules around the van (engine, trans, instrument cluster, etc) communicate via a two-wire “CAN bus” network.
Once you stop the engine and turn off the key, the modules all take a bit of time to tidy up and shut down gracefully.
Waiting for the odometer lamp to extinguish is a good indication that this has occurred.


05-11-2019, 10:35 PM
No, the next step is check codes again. so is it a matter of just waiting a minute or so?

05-11-2019, 10:51 PM

05-12-2019, 12:44 AM
Hard to believe those are Daimler instructions. Where did they come from? Chinese code reader?

05-12-2019, 03:51 PM
You can watch your CANbus (and other bits) go to sleep .... the instrument panel display takes 45 seconds before it winks out.

I'd certainly say that it's all tucked into bed by the time 2 minutes have elapsed (and probably only 1 in a T1N).

With a clamp-on ammeter you can also watch the current draw from the battery take steps downward after engine-off/key-out.

Scanner activity may kick it back awake a bit.

The T1N uses quite a bit of direct-wire communication ... unlike the NCV3 which is almost all CANbus.