CAN bus communication issues | Tech Minute 

Man I wish this guy responded

Look at good diagram for the location of the resistors, on a full system scan can you communicate with any modules? Partial or no communication will dictate the diagnostic direction.

@@rodvan-zeller6360 hi! That was last year. I did manage to find a solution to the problem. One of the modules (I can’t remember now..) by the glove compartment, I pulled each connector off one by one then putting back on. Assuming… there’s a bad connection on one of the pins or weak crimping… the problems went away! Months later… intermittently the headlights continued to stay on after shutting the engine off and turning off the headlights. That got worse to the point the lights stayed on all the time each time I shut the engine off. After 5 minutes, the lights automatically turned off. One day the low beam went out then later, the high beam went out. I discovered the light socket was fried! Resistance measured across it. I replaced the socket and headlight… problem solved!

@@kjarby69 Thank you for the reply. Glad you solved the issue.

did you try using a different scanner

Yea, I bought a $50k newer model truck, then it got hit by lightning... giant paperweight now... wish I would've bought a 1972 Chevy Pickup and cherried it out instead!! 🤣

@Herb Moore Maybe I'm wrong but if your paying $800 plus a month for a vehicle for 8 years than why not just buy an older truck and fix it up, dump $800 month in it and the value goes up. I just don't like new vehicles, too must plastic, they look cool and have a lot of power but too many sensors and issues that can go wrong

@@HerbMoore3 Think about all the flood cars out waiting to be sold to some unsuspecting buyer

I have a 2003 C230 Kompressor with 226k miles. I now have a pid P0600 “CAN Communication To Control. Module ESP is Faulty” showing in my OBD2/scan tool. Car is running good. Any suggestions will be highly appreciated. No engine light present.

agree

It depends on the car. You need to look at the schematic for the high speed communication bus and follow the wires in the car.

The voltage is regulated near 2.5 volts, loss of a terminating resistor will have little effect on the voltage but may have a large effect on the way the pattern looks on a scope.

Not all vehicles are connected to the CAN and the DLC OBDII connector, how was you testing at the OBDII? If you hook up a scope (only, no scanner comm) to the CAN HI and CAN LOW pins at the DLC and if there is a GATEWAY involved, you will not get much action on your scope, if you monitor the CAN with your Scantool (in scan mode), the Gateway now knows its a NODE connected and it passes the CAN patterns to the Scantool Scope screen.