PCM Hammer will not read P59

[woog74]

I will admit I'm new. But I've used PCM Hammer before without issue. I am doing another swap and bought another running donor truck. 03 Tahoe P59 PCM. Went to delete Vats and disable the usual emissions codes via Universal Patcher, can not get PCM Hammer to read Entire PCM. It is connected, "Read Properties" works fine. Go to "Read Entire PCM", and within one minute it gives me an error for unable to read. Battery voltage is good, plus I have a maintainer on it. I can scan the PCM with my Snap On Scanner and watch live data with the truck running. Anyone have any suggestions I could check/try?

[project_x]

I know this is old... But did you ever get to the bottom of it?

[woog74]

I know this is old... But did you ever get to the bottom of it?

Yes I switched to a bench harness and it worked fine.

[2xls1]

P59 vehicles can sometimes be difficult to read or write if they have aftermarket radios with after market chime adapters. Some remote start and alarms can interfere also when they tap into the ALDL data line wire near the plug. You can try pulling the radio and radio amp fuses or pull the radio and unplug everything after market from the in dash harness.

[woog74]

P59 vehicles can sometimes be difficult to read or write if they have aftermarket radios with after market chime adapters. Some remote start and alarms can interfere also when they tap into the ALDL data line wire near the plug. You can try pulling the radio and radio amp fuses or pull the radio and unplug everything after market from the in dash harness.

Vehicle had no radio, and no alarm or remote start. I tried removing all the fuses other then the ones essential to the PCM but I could not get it to work. Worked immediately with the bench harness, and I have flashed it several times in the truck that it is swapped into. I didn't bother looking at the wiring diagrams for powers and grounds on the donor vehicle, but I was guessing there were other modules turning on from the PCM power fuses so the can bus system had too much activity on it in that particular vehicle. Just my own theory though.