02 in limp mode

[dcamilleri]

I am trying to help a friend out of a bind. He has an 02 HO 6speed that went into limp mode this morning. I hooked up my scan tool and pulled lots of codes: PCU 1693, P0121, P0562, P0575, P0606, P0342, P0117, P0112, P1488, P0237. I ran a data stream and got 0 voltage reading for battery voltage, 0 volts for engine temp, (but engine temp registered 188deg) 0 volts for oil pressure. The temp gauge on the dash is burried on the hot side and when I checked setting through another setting it showed 293 deg.(according to pcm) TPS voltage is normal and changes with the throttle. I cleared codes and they came right back. I cleaned battery connections and checked grounds. I disassembled connectors to ecm/pcm on main wiring harness and applied dielectric grease. I disconected plug to coolant temp sensor and then the scan tool would show 5volts, engine would surge bad. With key on and engine off scan tool would show actual battery voltage but as soon as engine is started battery voltage on scan tool would drop to 0. Actual battery voltage at the batteries is 14+ volts. Engine revs very slowly and won't rev past 2000 rpms. I am pretty sure it is in limp mode. He has a power puck and I disconnected it for all tests. Anyone seen this before? Truck has 36,240 miles. Thanks for any ideas in advance. Dave