The attempts were made in-car, I will check the connections and wiring. The voltage did not drop below 12.7 during the attempt.
Thanks for the tips, I will let you know the results of the wiring inspection.

I am using an 'OBDLink SX' usb interface and have used it successfully to read and write to 5 other PCMs just not this one. The log is: [06:40:36:188] PCM Hammer 021 [06:40:36:220] Friday, June 24 2022 @06:40:36:22 [06:40:37:202] Voltage: 12.4V [06:40:37:218] Elm ID: ELM327 v1.4b [06:40:37:249] Scan...

Hi, New member here. There is a huge trove of information in the forum but I have been unable (maybe because of lack of knowledge on my part) to locate a reference to the type of error I am receiving from pcmhammer v21 when trying to read the P59 in my 6 liter S-10. I get several 'Unexpected respons...

Stepper motor controllers energize different poles of the stepper motor to initiate and maintain rotation, they will not operate a standard wound motor with brushes. I believe there are converters from stepper motor controller output to brush type motors.