We tried to hook to one of our company trucks today the has a telematics system on it. IDS would not talk to the PCM. It said unrecognized pcm. Does that telematics system lock you out? We wanted to change the tire size and enable the daytime running lights

 

If it's plugged into the pcm it could very well interrupt communications. Un-hook it and try again.
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We did try that, and it did not work. One of the other trucks that does not have the telematics locator installed yet lets us communicate with it just fine. I wondered if they flash the pcm somehow to let the pcm talk to their module. The ids sees the pcm but as unrecognized even with the device unplugged. We tried plugging into the oem obdII port that they moved up under the dash to the junction connector.

 

Check the fuse box for a blown fuse, do NOT rely on visual, use a test light.
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