Can program but not communicate
Hi guys, I have this auction Freestyle from a dealer, It has been to several other shops, it had no communication with PCM, all other modules communicate.
I checked all my powers, grounds and communication pins at the PCM, every thing tests good so I condemned the PCM.
Customer supplied a used PCM, I programmed it with the IDS using blank module programming with no problem, when it completes and trys to id the vehicle it will no longer communicate.
I can go back and program it over and over with no problem with the old PCM or the replacement with no problems or errors but I cant communicate with it after. Not sure what I'm missing
Hi Charles, Try communicating with an aftermarket tool. First try vehicle specific then OBDII Generic. It may be a problem with your VCMII. -Mike
I had a fleet that their inline DLC GPS units would do this. It through me for a loop at first, but all I had to do was unplug it.
That might be a DLC pin fit issue. Try another scan tool.
Chuck, Does the vehicle run? If not I have experienced this situation with other Fords when the FEPS line is shorted to power. When this happens the PCM will go into a no communication mode but will be programmable. Pin 44 at the PCM/ pin 13 at the DLC should have no voltage present unless programming.
I'm not sure how VREF output acts during programming, but if the module is powering up properly even with no comms, you should see a Vref at any easy to reach Vref sensor (TP, IAT, ect.)
No vehicle specific communication, only communication is with a snap on OBD2 IOS15765-4(CAN) with very little and incorrect data, no codes. I have not found anything in tapped or plugged in to the DLC or communication lines. I have no voltage on pin 13 of the DLC. Good to hear from you Mark, bought … last year but still have Advanced Diagnostics MDG. 5V reference is good after
5V Vref is good, that means that the PCM should be in a powered up state, Do you still have the ids?? Have you run the network test to evaluate for networking faults on the bus?? Might not be a bad idea to scope the HS can and just make sure the patterns are not corrupted. Have you checked the terminating resistance?
Hi, not sure if this would help since you already tested power supply. When checking powers and grounds did you load test each circuit?