2000 Cherokee Classic - No Start Problem

Engine cranks, no start.
OBD II gives me Code P1694 - Fault in Companion Module

With ignition to ON, after about 1 minute, Check Engine Light Illuminates and Odometer reads 'no bus'.

Any ideas?

Thanks
Dan

In my unexperienced opinion, this sounds like a computer problem.

Did this just happen all of a sudden, or have you had other problems with it?

First time, no previous issues with the computer

I love it. I really do. It's like there's only one thing that ever goes wrong on these things. Oh, sure it could be something else, but my money's always on the big-daddy pain in the caboose, the mother of all Cherokee/XJ troubles, but I digress. Sorry.

1st- Check the plugs to the PCM(computer, drivers side fender under the hood, next to the airbox- [you'll see 2 large wire harnesses]{unless they moved it in 2K?Aloha?}) for loose connection or corrosion.

2nd- Read this thread-> http://www.automotiveforums.com/vbulletin/showthread.php?t=708327

3rd- Read this one->
http://www.naxja.org/forum/showthread.php?t=902504&highlight=p1694+no+bus

~Good Luck! Oh, yeah. CPS (Crankshaft Position Sensor)
here- http://www.lunghd.com/Tech_Articles/Engine/Basic_Sensors_Diagnostics.htm

Solution - Crankshaft Position Sensor was shorted out.
Thanks for the Help
Dan

I have a seemed problem, but the engine start and work fine.

The basic problem is that sometimes and suddenly the instrumental panel does not show information of RPM and Car Velocity

I did scan today and I found that the ECU had stored the code P1694 "Bus Communication With Engine Module"

the company that sold to me the scantool says:
---------------------------------
That code indicates a lack of communication between the Engine Control Module (aka PCM) and another computer module in the car. "Cleaning" the connectors is likely NOT going to fix this, but you could if you want. They are generally hermetically sealed and in most cases gold plated, so "dirty pins" are very unlikely

From your description it sounds like the problem is in the network wiring between the PCM and possibly the Instrument Panel Module/Body Control Module.
---------------------------------

I do not think that the problem be the Instrument Panel Module because the scantool can not read the data from temperature, RPM and other signals, just can read the signal from Throttle position sensor (TPS)

I would like to know if I unplug the ECU cable, the computer of the Cherokee classic could lost its program.

The other weird thing is this non key light at the upper left corner of the panel

can someone help me with some ideas? :uhoh:

http://fotos.miarroba.com/thumb/2D47BB9FCF284772DE0B274772DE0A.jpg (http://album.miarroba.com/ertario/1/1/)


http://fotos.miarroba.com/fotos/c/9/c901f2eb.jpg

I have a seemed problem, but the engine start and work fine.

The basic problem is that sometimes and suddenly the instrumental panel does not show information of RPM and Car Velocity

I did scan today and I found that the ECU had stored the code P1694 "Bus Communication With Engine Module"

the company that sold to me the scantool says:
---------------------------------
That code indicates a lack of communication between the Engine Control Module (aka PCM) and another computer module in the car. "Cleaning" the connectors is likely NOT going to fix this, but you could if you want. They are generally hermetically sealed and in most cases gold plated, so "dirty pins" are very unlikely

From your description it sounds like the problem is in the network wiring between the PCM and possibly the Instrument Panel Module/Body Control Module.
---------------------------------

I do not think that the problem be the Instrument Panel Module because the scantool can not read the data from temperature, RPM and other signals, just can read the signal from Throttle position sensor (TPS)

I would like to know if I unplug the ECU cable, the computer of the Cherokee classic could lost its program.

The other weird thing is this non key light at the upper left corner of the panel

can someone help me with some ideas? :uhoh:

http://fotos.miarroba.com/thumb/2D47BB9FCF284772DE0B274772DE0A.jpg (http://album.miarroba.com/ertario/1/1/)


http://fotos.miarroba.com/fotos/c/9/c901f2eb.jpg

sounds like the imfamous instrument cluster connection. some people take the cluster out clean and tighten the connection and problem goes away! next time it happens pound the top of the dash and see if the problem goes away!

Solution - Crankshaft Position Sensor was shorted out.
Thanks for the Help
Dan

I was going to mention that....plus to disconnect the battery and reconnect it to recycle the electronics.

sounds like the imfamous instrument cluster connection. some people take the cluster out clean and tighten the connection and problem goes away! next time it happens pound the top of the dash and see if the problem goes away!

I agree about taking the instrument pack out. There is a known problem with the harness being too short and pulling out the connector. Possibly involved with a factory fix for this. (Do some searching.)

sounds like the imfamous instrument cluster connection. some people take the cluster out clean and tighten the connection and problem goes away! next time it happens pound the top of the dash and see if the problem goes away!

I agree about taking the instrument pack out. There is a known problem with the harness being too short and pulling out the connector. Possibly involved with a factory fix for this. (Do some searching.)

Thanks for your answers.
I will clean the cluster connector now. I do not think that it be the problem because the laptop can't read any signal neither, only it can see the TPS signal.

http://fotos.miarroba.com/thumb/1E47BC92A52C4773D0E2334773D0E0.jpg (http://album.miarroba.com/ertario/0/2/)
http://fotos.miarroba.com/fotos/6/5/6569a1b5.jpg

:rolleyes: thanks again

you not only have to clean it but you have to get into the connection with dental tools and tighten the female pins up so the snug against the male tight! also look for oxidation in the connection. lastly put a dielectric grease in it to protect it in the future. but make sure the dielec grease is non-conductive! mike

p.s. i believe the laptop gets the info from the BUS (via the obd2 connector) and when the cluster connection is down there is no-bus!

Hello guys,

I was working on my Cherokee Classic 2000; and I will present a resume of my recent activities

First that all, I discovered that for extract the cover on the control panel you must extract first the high bean button from the inside; pushing a little button that release the switch button because the hole is too tiny for let it pass.

http://fotos.miarroba.com/thumb/2847BE3B5F2E4775799D344775799A.jpg (http://album.miarroba.com/ertario/1/3/)http://fotos.miarroba.com/fotos/c/1/c1fae720.jpg

You must pull tight before quit all the screw for release the cluster from its two connectors

http://fotos.miarroba.com/thumb/2847BE3D3C3847757B7B3447757B77.jpg (http://album.miarroba.com/ertario/1/4/)http://fotos.miarroba.com/fotos/9/b/9b1b712c.jpg

http://fotos.miarroba.com/thumb/2A47BE3D8F3247757BCF3647757BCA.jpg (http://album.miarroba.com/ertario/1/5/)http://fotos.miarroba.com/fotos/b/c/bc065702.jpg

I could see that the pins was corroded with carbon depositions

http://fotos.miarroba.com/thumb/1547BE3DF83947757C393347757C33.jpg (http://album.miarroba.com/ertario/1/6/)http://fotos.miarroba.com/fotos/a/2/a2949068.jpg

I tried to clean the pins with a commercial cleaner but it was not enough, then I followed the 2000izusu’s advice; I did brush every pin with a screwdriver.

http://fotos.miarroba.com/fotos/0/e/0e4ebc8e.jpg

http://fotos.miarroba.com/fotos/4/2/420ff043.jpg

The only thing that I could do on the green male connector was spray it with the solvent.

http://fotos.miarroba.com/fotos/7/9/792528c5.jpg

I assembled the car again, and followed the AlohaBra’s advice and unplug the battery for reset the electronics.

http://fotos.miarroba.com/fotos/b/d/bd450cf6.jpg

Finally the problem go away, but I had my Cherokee on intensity care for yesterday and I had no problem with the instrumental panel; the Vehicle Theft Security system (VTSS) light is off and the tachometer and the other gauges are working again.

BUT…

2 hours ago, I re-scanned again looking for DTC’s codes and I found the P1694 again, but the gauges are working

http://fotos.miarroba.com/fotos/8/2/82ffc283.jpg


Now I am remembering that once I saw that the instrumental panel was death, all the gauges was indicating no measurement that tell me that I have to clean better both connector male and female because the probability that the problem be the cluster is high.


Thanks to everyone for the help I will keep you informed

cool sounds like progress. also if i remember correctly their is a tsb on this problem. and it calls for replacing the connector with a re-engineered one. i would say that is a last resort because you have to splice it in.

I got the same problem again, but I fixed up, I will write the ultimate solution procedure on next weekend….
:icon16: :naughty: :p

you not only have to clean it but you have to get into the connection with dental tools and tighten the female pins up so the snug against the male tight!

Ultimate solution

First that all
Thanks guys for your help and special thanks to 2000izusu for his/her advice, because it was the right diagnostic.
The work consist in a basic and simple connector adjustment for get it tight its pins
After remove the entire cluster panel and the other things I did detach the male connector from his support.

http://fotos.miarroba.com/fotos/5/2/528efe62.jpg

http://fotos.miarroba.com/fotos/3/c/3cba509f.jpg

http://fotos.miarroba.com/fotos/b/e/be1e4fd2.jpg


Taking off the female pin from male panel connector.

Now you can observe the deformation inside the female pin that causes a slack connection.

http://fotos.miarroba.com/fotos/1/a/1a9f6de6.jpg

http://fotos.miarroba.com/fotos/6/2/62196cd8.jpg

The solution was deform back the laminates inside the female connector with a small rigid tool, I did use a compass for get it tight again, and repeat the procedure to all the female pins of the male connector.

http://fotos.miarroba.com/fotos/5/a/5ab71339.jpg

In the picture you can see that all the females are deformed.

When all the connectors were fine, do clean it up again with the solvent. then I did scan the ECU and the problem leaves my car.

The other problem that I had with the airbag module I fixed up this same lucky day, it was a broken cable from the wiring cluster, and now everything is all right, and no spare part was bought

:naughty: :smooch: :smokin: :grinyes: :lol2: :lol:

thanks again for your support

Great! glad you didn't have to splice any thing!