Hey guys, I've been reading all of the threads on here about the P0720 code and the Speed Sensors. I must be missing something. Have a 1997 Jeep Grand Cherokee Laredo (4.0 I6) throwing a P0720 code. I have replaced the OSS twice, replaced the wiring harness on the OSS with a new one, replaced the VSS, replaced the PCM, replaced the TPS. Still getting the P0720 code. I can't find the G106 ground on my vehicle that was in another thread with pictures. I have checked 2 other grounds that I found on the vehicle. The vehicle is also stalling/trying to stall out at times. I can flutter the gas and keep it from dying. Image below.

 

Try checking for 5VDC supply on the OSS. This supply also supplies the throttle position sensor. the 5V originates from the PCM pin 31. Also the ground for both originates at the PCM pin 4. So you should have 5v at both sensors and the 5v ground at both sensors. Measure between the sensor ground and the +5v at each sensor. This is in the wiring diagram.

 

I got 1V at the OSS and 5V at the Throttle Position Sensor and several other sensors. I couldn't get any readings on the PCM, I don't think I have the right connector for my multimeter or something.