So a few weeks ago my guage's stopped working in my 00 XJ. (Lights and everything work, gauge's just dont move, odometer says "no bus" and my airbag light is on)

I found out that if i hold the horn down, the gauge's work, the "no bus" message goes away, and the airbag light goes off. Until i stop pressing the horn...

What is the connection between these two? Where should i start looking to get this sorted out?

Fyi: cluster works fine. i did the cluster test, and purchased a 2nd known to work cluster that also works perfectly. I have checked all fuses in the engine bay, and interior fuse box. They do not blow, and all fuses are good. I have checked and cleaned every single ground in the engine bay. The CPS is brand new, and tested to be working according to the tests on these forums.

 

Sounds like wires shorting against each other somewhere or bad grounds. I'm sure cruiser54 will be here soon....Listen to him, trust me. A lot of his info has really helped me and my Jeep.

 

bad ground or bad connector on back of instrument cluster

 

Thanks so far guys.

Is there a specific ground i should be looking at/for?

I know about the cluster plug/pigtail update. And it seems that maybe 1/4 of the time updating that plug fix's anything. I did clean all contacts on the cluster, slightly bent them over for better contact in the sockets, and dialectric greased them with zero results. I highly doubt it is the cluster plug, but i guess for $7...its worth doing to eliminate as a possible fault.

 

Could be a bad clockspring.

Go to your TPS, unplug the electrical connector.

Using a Voltmeter, probe (+) the harness side of the connector at the pin cavity for the Organge wire and probe (-) to the battery negative post.

With the ignition key to RUN, without cranking the engine, you should see around 5 volts on your meter. If it is above 5.5 volts there may be battery voltage leaking through the clockspring cruise control circuit, from the horn circuit, to the PCM.

Honk the horn and see if the voltages changes.

Get back with your results please.

 

12.2V to 14.1V with key on, does not change by honking the horn.

With key off 00.2V

 

On 89 there a dash ground by left foot area ...not sure about yours. did any work be performed b4 this occurred

 

Your instrument cluster has a ground at ground post G108. The wire is an 18 ga Black/light green tracer. G108 located on the dash frame near the headlmp switch. If someone was fooling around under the dash they may have left the ground wires loose. The radio is also grounded at G108. There's lots of ground wires at G108. Check it out.

 

Sounds like a classic clockspring issue.

You can isolate the source of the 12 volts by removing the horn relay in the Junction Block (in the passenger footwell).

You need to remove the cover off the JB to get at the horn relay.

After removing the horn relay, check the voltage at the TPS again. If it dropped to around 5 volts, consider the clockspring bad. If the voltage remains at 12 volts there's another short somewhere that needs to be chased down.

If it is resolved the the horn relay dropped the voltage to 5 volts (normal) the horn relay can be left removed until you line up a clockspring and replace it. They come in different flavors so if you have cruise control, a new one will cost a few bux more.

 

Check ground g108.....

 

thank you so much, I will check this tomorrow after work, please stay tuned.

 

thanks, I will look at G108 tomorrow as well. I have tried looking for it once before with no luck, but the drawing helps a little. thanks.

 

Google is our friend ...lol..

 

so I just researched clock springs, sounds like the culprit, but id still rather test before throwing more money into this jeep. I spent some of my "wheel and tire" money trying to fix this issue with zero results s far.

 

Agreed grounds easy check...