Van turns over but won’t start. Code shows throttle
body so replaced that. Now still won’t start but is
throwing System Voltage Low. Tried jump starting,
cleared codes and nothing.
First, make sure your car battery is good and does hold a charge which measures above 12 volts. That must be a known first and foremost. If the battery proves to be reliable/good, then next item to check would be system grounds. Make sure they are well cleaned and tight. If these do not fix the problem, it gets more difficult. Need to troubleshoot wires/wiring/harnesses. If they have no troubles then....the dreaded pcm. But really pcms are getting more dependable and it should not be that.