Saturn Repair Problems? Ask a Mechanic for Answers ASAP
Hi, my name is Barry. Welcome to Just Answer. I would be happy to help you with your Saturn SC-1. I believe that has a one wire o2 sensor. Are you comfortable testing a few wires with a DVM?
Ok. Unplug the o2 sensor and the connectors on the pcm.
We need to test the wire connector for the o2 sensor vehicle side for continuity to ground and for dc voltage.
Unplug the o2 sensor and the connectors on the pcm.
Set the dvm to ohms.
Test the vehicle side of the o2 sensor wire to the ground terminal on the battery.
What does it read?
Then set the dvm to dc volts. Turn the key to the on position. Do the same test as above between the o2 connector and negative battery terminal.
Did you perform the test with the pcm disconnected?
Try it with the pcm disconnected. I want to see if the pcm is making the voltage or if the wire is shorted to power somewhere.
Ok. There is a short to voltage somewhere in that wire. You can try to locate the short or you can run a new wire from the O2 sensor to the pcm.
I think your on the right track. Just let me know how it goes tomorrow.
It sounds like the short to voltage is internal to the pcm.
There is most likely a short to power going to the pcm on another pin. There shouldn't be any voltage on the o2 sensor pin on the pcm with the o2 sensor unplugged. I would start testing the wiring to the pcm for power. Let me know what wires have power on them and maybe we can find your issue.