Overhead console questions

I have read over this guide a couple of times regarding putting a ZJ trip computer in an XJ, I have the consoles and BCM from the junkyard already, but two things are keeping me from getting this project started.

1) I have no Sentry Key Module connector, it's nowhere to be found. Do I still have the option of wiring the BCM under the dash using some other wires there? If so does anyone know what wires I can tap in to?

2) If I plug the temp sensor into the connector at the bumper, where can I find it's wires in the cab to tap in to?

Thanks

I've done some digging in the FSM, which contained much more wiring info that I had previously thought, and have answered my own questions. So, here they are for anyone else who wonders the same things.

1) Yes, you can also tap in to the OBDII diagnostic port, pins 3 & 11 are the CCD bus.

2) The FSM shows the ambient temp sensor circuit coming into a large connector just below the instrument panel, to the right of the driver's legs. The connector is called C201. The pins to tap into are 32 and 35.

I wish I could include connector diagrams, but I can't figure out how to pull them out of this pdf. So, obviously the FSM will still need to be referenced when doing this.

You can tap into the CCD bus basically anywhere you want. The OBDII port works, so does the cable leading to the TCU (right above the gas pedal on the tranny tunnel.) You're looking for the white/black wire and the (I believe) violet/brown/green (it's some combo of these, I just forget which) wire. The white/black is CCD-, the other is CCD+.

EDIT: it is violet/brown.

Also, just a heads up - PLEASE don't post pirated FSM links or large excerpts from the same. Review the fair use guidelines (they're on wikipedia) before posting a diagram, generally small amounts of data are fine but whole pages and diagrams aren't. Not accusing anyone of doing this here, as no one has, but it comes up regularly and I'd rather warn people before they do it than have to hand out infractions after the fact.

sudo chop said:

2) The FSM shows the ambient temp sensor circuit coming into a large connector just below the instrument panel, to the right of the driver's legs. The connector is called C201. The pins to tap into are 32 and 35.

Click to expand...

This is a good start, Sudo, did you ever figure this one out?

sudo chop said:

I've done some digging in the FSM, which contained much more wiring info that I had previously thought, and have answered my own questions. So, here they are for anyone else who wonders the same things.

1) Yes, you can also tap in to the OBDII diagnostic port, pins 3 & 11 are the CCD bus.

2) The FSM shows the ambient temp sensor circuit coming into a large connector just below the instrument panel, to the right of the driver's legs. The connector is called C201. The pins to tap into are 32 and 35.

I wish I could include connector diagrams, but I can't figure out how to pull them out of this pdf. So, obviously the FSM will still need to be referenced when doing this.

Click to expand...

Yup, you can tie into the CCD bus anywhere you want. I wish I could make an edit to my original writeup, but 97 and 98 XJ's did not have a sentry key option, so there is no SKIM plug to tie into.

I think the CCD bus also goes through some of the plugs on on the fuse box junction block - if you wanted a handy area to tie them in without having to run all the way over to the OBDII port.
EDIT: I take this back, I went and looked through plugs C1-C9 on the junction block, no CCD bus anywhere there. So either the OBDII port or find another source(gauge cluster, OHC etc)

If you need anymore help PM me during the install.


Second thought, I do know where the CCD bus does run through down there, on the wiring plug for the OHC the CCD bus runs through there, its also a pretty well buried plug thats a PITA to deal with when doing a stock XJ wiring harness swap for the OHC.

Is this CCD Bus data available on the 1996 XJ? It would be good to get the late model over head console to display every thing instead of just the temperature and the compass.

techno1154 said:

Is this CCD Bus data available on the 1996 XJ? It would be good to get the late model over head console to display every thing instead of just the temperature and the compass.

Click to expand...

Yes the CCD bus would be on a 1996. I've talked about this before with some different people, but no one has ever followed through on implementing it, and it all remains untested.

I don't have a 96 so I can't test it, I've given people leads and told them the various ways it might work, but no one has taken the initiative that I know of.

The jist of it is, a 93-95 ZJ OHC might be the solution. Since the 96 is switchover year it has the newer type of ECU, the question is if it transmits the information needed to calculate fuel consumption, distance to empty, miles etc. I'm not sure what kind of information the OHC needs to calculate the fuel economy, but one would assume it needs some speed information. Since the 96 uses an electric speedo you might get it to work with a ZJ BCM, but I think the 96 XJ doesn't tie the speedo into the XJ, but rather into the gauge cluster like on the 95 and older.

So if you used a ZJ BCM anyway for the temp signal like in the writeup about, and then if you also tied in your VSS input to the ZJ bcm as well as your speedo, or if the 96 ECU either has the pins on it for the VSS, or if you added the pins for the VSS and the ECU transmitted that anyway when added, you could probably make it work.