Hi all,

I'm working on my 96 xj 4.0 manual trans.

I am not getting 12v to the o2 sensors.

I have checked the asd relay wiring.
With the key on run (Koeo) I am not getting power thru the relay.
The fuse is good, I have power into the asd thru the red/black wire from the fuse but it’s not getting to the dark green/orange wire.

If I remove the relay and jump the red/black and the dark green/orange the o2 sensors are getting 12v. So that side is good.

Checking the other side of the relay I have power from the ignition switch to the asd thru the dark blue wire.

What’s missing is a signal from the ecu. I have pulled the connector from the ecu and checked for continuity on the dark blue/yellow wire to he asd and it is good.

My question is how to test the computer switching.

Is it a ground signal or a 5v or 12v? I’m not sure how to test that part.

I know what pin to test but don’t want to short out the ecu by doing something wrong.

Thanks for your help in advance.
Joe

This all started when my exhaust broke in front of the cat converter and the exhaust was held up by the o2 sensor wiring. I can’t see any damage to the wiring.
I replaced the rusted cat.