I'm new here so hello everyone. I have a 2003 3.4l and I just put a new tranny in. Well it's not starting and I connect my scanner up to it to see if I can get any codes and its telling me it has no comms. First, can I get any ideas why I'm not getting it to start? It's displaying the security light and it clicks...nothing else. And please tell me why I'm not getting comms to my ecu adapter?

 

If your scanner isn't communicating with the PCM double check all your wiring connections and check the fuses for the PCM and the front power outlet. If I remember correct, the power outlet circuit also feeds the OBD II plug under the dash.

Edit: After you gain communication with the PCM you may have to do a security relearn in order to get the engine to turn over and start. Doing a search for 'security relearn' on the forum will bring up info on how to do that procedure.

 

Where's the front power outlet?

 

I might add that the headlights are on and it randomly may blow the horn quickly. I have to unplug the battery or it will get drained. I don't know if that'll help but I hope it does.

 

I just understood what was being said. Let me say that the cigarette outlet does work and all fuses are good. I can't think why the ecu isn't communicating with the scanner when that scanner works with another ecu. I've also used another scanner with no success. What else would cause no comms with the ecu? And I'd also like to say that the relearn procedure didn't work as well.