NAXJA Forums -::- North American XJ Association  

Go Back   NAXJA Forums -::- North American XJ Association > NAXJA Unibody Jeep Technical Forums > Jeep Cherokee XJ (1984 - 2001) > OEM Tech Discussion
HOME Member FAQ Sponsor Info Rules Bylaws E-Mail

OEM Tech Discussion Forum for OEM (Original Equipment) or stock XJs and MJs.

Reply
 
Thread Tools Display Modes
  #1  
Old August 22nd, 2006, 14:26
BDHershey BDHershey is offline
NAXJA Forum User
 
Join Date: Oct 2005
Location: Lexington, SC
Posts: 32
Question Error codes P1698 and P1687

Twice in the last two weeks the check engine light in my '99 XJ Sport (with 4wd, 4.0, and Automatic tran) has come on and then gone off after a day or so. I was in getting new tires at the Goodyear where my buddy works and he plugged it in to their diagnostic machine and got error codes:

P1698 - No transmission bus
and
P1687 - No Mic bus

the jeep has been running fine, trans shifting fine, and the speedometer and odometer working fine. What do these mean and any idea what need to be done to fix them? I searched here but didn't find what I was looking for.


-Hershey

Last edited by BDHershey; August 22nd, 2006 at 14:33.
Reply With Quote
  #2  
Old August 22nd, 2006, 14:52
foxwar71 foxwar71 is offline
NAXJA Forum User
 
Join Date: Mar 2005
Location: Foxboro, MA
Posts: 13,509
Re: Error codes P1698 and P1687

ive been havin the same problems with mine. i jsut took all the connectors out of the tranny, cleaned the out, threw some di electric grease in there adn havent had them come back on yet
Reply With Quote
  #3  
Old August 22nd, 2006, 15:26
BDHershey BDHershey is offline
NAXJA Forum User
 
Join Date: Oct 2005
Location: Lexington, SC
Posts: 32
Re: Error codes P1698 and P1687

How long has that been? I can't even find these codes in my Haynes manual.

-Hershey
Reply With Quote
  #4  
Old August 22nd, 2006, 16:01
Matthew Currie's Avatar
Matthew Currie Matthew Currie is offline
NAXJA Member #760
 
Join Date: May 2002
Location: Vermont, land of big clay
Posts: 7,014
Re: Error codes P1698 and P1687

The 99 FSM lists the codes this way: 1687, "no MIC bus" no "CCD/J1850 messages" have been received from the instrument cluster. P1698 is the same n-bus failure from the Transmission controller. I'm guessing this means that when the system starts up it checks for feedback, and if it doesn't find the connection satisfactory it sets those codes.

Since problems with the connector to the instrument cluster are a common complaint with this vintage model, I'd start there, with cleaning and replugging the instrument cluster and the transmission control unit.
Reply With Quote
  #5  
Old August 22nd, 2006, 16:31
BDHershey BDHershey is offline
NAXJA Forum User
 
Join Date: Oct 2005
Location: Lexington, SC
Posts: 32
Re: Error codes P1698 and P1687

I had the A/C evaporator replaced a month or two ago at the dealership. I was told they would have to tear down the dash. Possible reason? Though it has just started. Where is the TCU located, I haven't found a reference to it in my Haynes either.

-Hershey
Reply With Quote
  #6  
Old August 22nd, 2006, 17:32
BDHershey BDHershey is offline
NAXJA Forum User
 
Join Date: Oct 2005
Location: Lexington, SC
Posts: 32
Re: Error codes P1698 and P1687

Update....

I think I found the TCU. On the center console stack in the drivers foot well? I saw it described somewhere else as about 4"x4" give or take. Silver. Aisin or something like that on it. That's what this looks like. Connections seemed firm. I didn't disconnect. If/when I do, what should I clean it with?

-Hershey
Reply With Quote
  #7  
Old August 22nd, 2006, 19:38
Matthew Currie's Avatar
Matthew Currie Matthew Currie is offline
NAXJA Member #760
 
Join Date: May 2002
Location: Vermont, land of big clay
Posts: 7,014
Re: Error codes P1698 and P1687

Quote:
Originally Posted by BDHershey
Update....

I think I found the TCU. On the center console stack in the drivers foot well? I saw it described somewhere else as about 4"x4" give or take. Silver. Aisin or something like that on it. That's what this looks like. Connections seemed firm. I didn't disconnect. If/when I do, what should I clean it with?

-Hershey
You can get non-flammable electrical contact cleaner in various places, including, at least in former times, Radio Shack, sold as TV tuner and control cleaner. That works pretty well usually. It might be sufficient just to unplug and replug the connector. No harm in trying it.

I don't have an automatic, so I don't know where the TCU is on a 99, but it will indeed be a little silver box that says "Aisin Warner" on it, so it looks as if you've found yours.
Reply With Quote
  #8  
Old August 23rd, 2006, 04:41
BDHershey BDHershey is offline
NAXJA Forum User
 
Join Date: Oct 2005
Location: Lexington, SC
Posts: 32
Re: Error codes P1698 and P1687

Last night I did unplug/replug. The contacts looked pretty clean thoug. We'll see what that does.

Thanks for the help so far!

-Hershey
Reply With Quote
  #9  
Old August 23rd, 2006, 07:04
Pioneer84's Avatar
Pioneer84 Pioneer84 is offline
NAXJA Forum User
 
Join Date: Aug 2006
Location: Lake George, NY
Posts: 68
Re: Error codes P1698 and P1687

Dont get the Radio Shack tuner cleaner get DeOxit its much better and its also sold at Radio shack its a 2 pack comes with progold .
Reply With Quote
  #10  
Old September 4th, 2006, 07:30
BDHershey BDHershey is offline
NAXJA Forum User
 
Join Date: Oct 2005
Location: Lexington, SC
Posts: 32
Re: Error codes P1698 and P1687

Update...

Light was off for about a week. But has now come back on. Disconnected/reconnected the TCU again and light is still on. Truck runs fine, and shifts fine, no problems there. But my wife and I switched rides for mileage reasons and am afraid that it may leave her stranded. Are there sources for new TCU's? Haven't had much luck on the internet other than some used ones. Any help is appreciated! Thanks guys!

-Hershey
Reply With Quote
  #11  
Old September 4th, 2006, 17:18
BDHershey BDHershey is offline
NAXJA Forum User
 
Join Date: Oct 2005
Location: Lexington, SC
Posts: 32
Re: Error codes P1698 and P1687

Hey guys any suggestions on where to find a TCU or TCM? If I go to the salvage yard are they pretty interchangeable or do I need to look for another '99? Also I was reading somewhere else on here that the TPS and TCM work pretty close together and that sometimes the TPS can cause tranny probs. Also that the TPS doesn't like water here at all. THis all started to happen after a torrential downpour here a feww weeks ago. I was out in the middle of nowhere delivering cookie for a church ministry and the flooded dirt roads I had to travel got the engine compartment pretty wet. Again I have had no driveability probs of yet but the light comes on for several days, then is off for several, then back on, etc. Since we traded I don't want the wife stuck somewhere. Thanks again for any suggestions!

-Hershey
Reply With Quote
  #12  
Old March 17th, 2007, 15:31
fallujah03 fallujah03 is offline
On a Time Out
 
Join Date: Mar 2007
Location: Danbury
Posts: 1
Re: Error codes P1698 and P1687

I just started getting the p1698 code as well as p1682 (voltage too low). After driving 7 hours through the rain. After parking at a rest stop for a while with the engine running to dry things out. My voltage came back up (from 9 to 14). Towards the end of the trip the tranny started slipping out of OD. I cleared the codes, cleaned the wire harness going to the PCM, and still had p1698 pop-up. Any advice before I bring it to a dealer with a better diagnostic tool then the one I keep in my trunk?

-1998 XJ 4.0L and Auto
Reply With Quote
  #13  
Old September 27th, 2021, 18:05
GunnyPortersxj GunnyPortersxj is offline
NAXJA Forum User
 
Join Date: Sep 2021
Location: southern maryland
Posts: 3
Re: Error codes P1698 and P1687

Quote:
Originally Posted by BDHershey View Post
I had the A/C evaporator replaced a month or two ago at the dealership. I was told they would have to tear down the dash. Possible reason? Though it has just started. Where is the TCU located, I haven't found a reference to it in my Haynes either.

-Hershey
Its located just above the gas pedal take the panel down under the steering wheel and look up to your right you will see it.
Reply With Quote
  #14  
Old September 27th, 2021, 18:09
GunnyPortersxj GunnyPortersxj is offline
NAXJA Forum User
 
Join Date: Sep 2021
Location: southern maryland
Posts: 3
Re: Error codes P1698 and P1687

Its located under the drivers side to the right of the gas pedal . Take down the panel under the steering wheel look up to the right and its right there.
Reply With Quote
  #15  
Old September 27th, 2021, 18:14
Unclewolverine Unclewolverine is offline
NAXJA Forum User
 
Join Date: Jun 2019
Location: Kansas
Posts: 512
Re: Error codes P1698 and P1687

I'm going to guess they took care of it since the last post was 14 years ago. . .
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
XJ error codes 92stroker Modified Tech Discussion 5 June 8th, 2006 07:49
error codes monkeysxj OEM Tech Discussion 10 December 3rd, 2005 21:36
'96 XJ error codes help... kee OEM Tech Discussion 7 May 27th, 2005 12:15
Error codes StuckXJ OEM Tech Discussion 15 April 16th, 2005 11:08
error codes on 96 Cliff OEM Tech Discussion 6 July 10th, 2004 11:15


All times are GMT -7. The time now is 17:39.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
NAXJA and NAXJA logo's Copyright NAXJA. All content/images Copyright NAXJA 1999-2014