Birty Dastards Jeep Club

Tech Forum => Workshop => Topic started by: Nosebolt on October 08, 2022, 05:04:45 PM

Title: O2 sensors and relays
Post by: Nosebolt on October 08, 2022, 05:04:45 PM
so got this new to me TJ and it has the wrong PCM fitted, it runs but have a correct one on the way so this might fix itself but I'm getting voltage issues on the O2 sensors no check engine light but see the codes with OBDII, they clear but come back when engine runs.

My question is should there be relays in the under bonnet fuse box for the sensors or is that just for Cal emissions?
Title: Re: O2 sensors and relays
Post by: Jonny Jeep on October 08, 2022, 05:33:43 PM
Just checked one of the FSMs (2000). Relays were used for O2 sensors for California and euro III emissions models. Don't know about other years without trawling through all the FSMs. What year is the TJ?
Title: Re: O2 sensors and relays
Post by: Nosebolt on October 08, 2022, 05:45:49 PM
2000 by VIN, 2001 by reg
Title: Re: O2 sensors and relays
Post by: Jonny Jeep on October 13, 2022, 07:49:56 PM
The VIN should normally be used to ascertain model year, so it should be a 2000 model as far as the FSMs are concerned. There is some overlap of model years when changes have happened, but the 00 and 01 FSMs are kind of combined with the 01 FSM being a supplement of the 00 FSM.

I'll see if I've got room to host the wiring diagrams in my google drive so you can download them.

Edit here are links to download...

2000 TJ Wiring
https://drive.google.com/file/d/1hCYQxXrd_fHbmnLoOJBm4fLriH87zLyf/view?usp=sharing

2001 TJ Wiring
https://drive.google.com/file/d/1d8XwHEsvrgK9fc8qD3LYJDAJqvIy87RR/view?usp=sharing
Title: Re: O2 sensors and relays
Post by: Nosebolt on October 15, 2022, 03:45:04 PM
Many thanks