I need a "no bus" expert
 

I have a 2001 Jeep cherokee limited. the no bus has always come and gone but now its permanent. I know there is tons of info on this common problem and I have read all of it. Hoping to get guidance in the order of what to check.

The service bulletin on this which says to replace the cluster connector applies to 98 and 99 models ( was told by jeep service no such bulletin for the 2001)

I pulled the cluster cleaned the contacts used dielectric grease and reinstalled.
still no bus.

where to next? should i still replace the connector? i read somewhere its mostly the right connector but from the drivers seat or front of the vehicle?

or should i start with checking the various modules on the bus system? there are a ton of them. ( CAM, CRANK, THROTTLE...ETC) or even a bad PCM.
uh this sucks, any help in which direction would be great.

The vehicle runs perfect just no gauges at all.

Go here and start at post #17.


http://www.jeepforum.com/forum/f11/i...33/index2.html

CCken I read through that whole saga and it was a bad cluster in the end. My jeep was running tip top so it has to be a connection issue or bad cluster I'm thinking. I read somewhere to hold the trip button with key to on but not stating the engine which performs a test of the cluster which i did and it ran through a series of actions. does this mean the cluster is good?

I'm tempted to get a replacement cluster before digging to china on this.

The cluster actuator test is a good test but it is done through the cluster's internal micro processor, not the CCD Bus. The cluster could test good but its connection to the CCD Bus may be bad.


Do the simple resistance and voltage checks at the DLC, like outlined in the other post, and see what you get. If the voltage(s) are low, the bias voltage from the instrument cluster may be at fault. If the resistance is not 60 Ohms, the cluster or PCM termination resistor may be bad.


Don't just shotgun an instrument cluster. It could be another module causing the problem.


Do those checks and get back.


In the mean time, line up a replacement cluster - just in case.

well i may have dodged a bullet because its working now. i cleaned the connector extremely well with contact cleaner and an eraser on each pin both sides. reconnected it with force but also forced the connection from the back side so i was positive i had good connection.

turned it back on and the no bus is gone. if it comes back on over the weekend then i will pick up where I left off.

Thanks for the help CCKen !! :thumbsup:

Good work.

Sorry i spoke to soon. it came back. I will pick back up with the post as you suggest and do more testing of modules and DLC

I knew you'd be back....


That's mean.

haha thats not mean Ken, you knew this problem would not go quietly.
i checked resistance at the DLC and the CCD bus was 60 ohms on the dot.

However i got zero on volts. unless I did something wrong I guess that means I have a bad module. right?

Ignition switch to ON/RUN, engine NOT running.


Pin cav 3 (+ probe), pin cav 4 or 5 (- probe).


Pin cav 11 (+ probe), pin cav 4 or 5 (- probe).


If you still get zero volts, switch the meter to 2 volt DC scale and see if you get a voltage.

Ken i need to get a multi meter. I used to work from milwaukee tool but the only meter i kept is CAT III 600-1000 volt clamp meter. lol little overkill for home and auto work.

turns out i already had a new multi meter. found it in with some work products.
2.37 volts on both for the CCD bus.

With good resistance and voltages on the CCD Bus the only thing I can point to is an intermittent poor connection of the two CCD Bus pins in connector C2 of the instrument cluster. Do the instruments display when these readings were taken?

no the instruments do not display when i took the readings. it only shows no bus and i think the air bag light is on. gauges are all at zero

i ran out for a short trip and it worked again. totally random. should i try a used cluster?
tried to find one at junkyard by me. no cherokees. lots of grand cherokees though. haha.

is there a procedure to test the cluster?