Computer Communications Problem Phenomenon

[BP]

Reatta Comrades <P>I took my first real “Road Trip” today with my (new to me) 1989 Reatta. I love to drive this car!! The car drove and performed marvelously … Except, about 3 hours into the trip the Dash Board Instruments and “Idiot Lights” went hay wire! Some were lit while others were Black – I had No indications of Speed or Gas Gage (Unlike Jim Houston’s problem “HELP! My Digital Dash Went Out “ my Test Light yielded no response. And the CRT Alarmed indicating “Computer Communications Problem Detected”. The sub page for vehicle status indicated computer communications problem and subsequent sub-page indicated VEHICLE COMPUTER COMMUNICATION PROBLEM DETECTED Service Check Required. Shortly after receiving the alarm and semi dashboard blackout, I pulled over and shut off the car. <P>When I restarted it a few minutes later all my indications returned. The CRT Diagnostic indicated NO Malfunctions and I drove on. Just after expelling a huge sigh of relief the dash indication flickered and disappeared again. <P>This same phenomenon occurred the following day on my return trip. All the CRT functions continued working. I used my cruise Control to monitor my speed and trip data to monitor gas consumption using “Range.” <P>When I got home I checked the owner’s manual and all the fuses in the panel and pulled and reinstalled the relays in the panel under the hood. I found No abnormalities. A quick trip to the store and back provided no repeat dashboard displays, but I hardly think checking fuses fixed this intermittent problem<P>I feel like a big sissy, whining about my Reatta problems already, but you all have been so kind. Seems Like the problem Jim Houston described (in “HELP! My Digital Dash Went Out “ is similar but not the same … any thoughts ????? <P>Thanks<BR>Bob P (aka BP)

[padgett]

Well you could try the recommened fix for an Apple III that malfunctions: lift about 18 inches and drop it.<P>Seriously, that sounds like a bad data line connection between the BCM and the IPX. Since the BCM is the easiest to get to, I would pull the glove box and reseat those connections first.<P>Now there are three possible error codes all put out by the BCM whic would help B334 (ECM data), B335 (CRTC data), and B336 (IPC data)<BR>- from the description it sounds like you were getting a 336 but can you confirm ? (Should be in History).<P>When it happened, did the defroster turn on ?

[BP]

Thanks for the feedback but I need an interpreter for a few things:<BR>1. What’s a the BCM and the IPX (I’m assuming they are some sort of electrical box and the BCM is behind the Glovebox)<P>2. How do I get access to (or determine) these error codes B334 (ECM data), B335 (CRTC data), and B336 (IPC data)<P>No changes in climate controls occurred when the dash lights spasm’d out. <P>It embarassing displaying my ignorance for all to see, but exciting learning new things about my car. I’ll look for the BCM behind my glove box today <P>Thanks <BR>bob p

[padgett]

This is why you <span style="font-weight: bold"><span style="font-style: italic">really</span></span> need the factory service manual (FSM). How to display/read the codes is in the FAQ on <A HREF="http://www.reatta.net." TARGET=_blank>http://www.reatta.net.</A> <P>BCM is the Body Control Module (computer) is a silver box (abt 6"x6"x1") with three connectors located behind the glove box (need a T-15 driver - no need to remove the light lens or hinge - to remove the box). <P>ECM (Engine Control Module) is another computer that looks very similar in the passenger footwell.<P>IPX (Instrunent Panel X(tension ?)) is the display device in front of the driver that shows MPH and all that. CRT (Catode Ray Tube - don't ask) is touchscreen above the console.

[Howard]

The error codes can be gotten from the CRT. Press the Climate control button. Once the Climate screen is displayed, press and hold at the same time the Off and Warm Key. You will have to press and hold for a few seconds. The Service Engine light will flash and watch for the codes. It will scroll from ECM to BCM and IP. Note the code numbers. Watch for the wording under the code. If it says Current, that problem is happening right now. If it says History, that problem and happened in the past, but is not a problem right at the moment. This is why a manual is a good thing to have. When you are finished, press the End key on the screen. Let us know what the numbers are. Howard

[BP]

Thanks for all the info. I (The family moron)will endeavor to crack the codes in the AM. Thanks again I'll keep you posted!

[BP]

OK - I followed the directions and the codes are as follows: E026, B420, & B552. All indicated 'History' codes. Other INFO presented on the CRT was "NO CRT CODES" and then "ECM?" <P>Also at the top of the screen were buttons on the left for YES & NO and to the Right were Override with Up & Down Arrows. I was afraid to touch any of these without further instructions.<P>I also ran the Codes with both the engine running and off. There was no change in the readings.<P>This car is so cool & You guys are Great! What's next?<P>bob p

[padgett]

EO26 is "Quad driver and can be a number of things (EGR, TCC, fans, purge)<P>B420 is related to various relays, such as couresy power, retained (key off) power, hi/lo beam headlight relay.<P>B552 is ECM "keep alive" power - this is set if you R&R the battery.<P>All can be caused by intermittant wiring problems but none directly relate to the IPX. I would clear all of them and see what comes back.<P>Have not seen this type of thing since moving to Florida but is apparently common in the north, particularly where salt is used on the roads.

[BP]

How do I clear off the codes?

[padgett]

If you go to each module in turn (ECM, BCM,...) and cycle through the selections, there will be one for each that says "clear history...". Push "yes".<P>You <span style="font-weight: bold"><span style="font-style: italic">really</span></span> need a service manual.

[BP]

I followed your directions and cleared out all historical codes. I checked for new codes the last two days No NEW ERROR Codes and NO repeat Dashboard Lights Phenomenons!! Thanks again my to my Reatta family "Wizards"! You have removed the Electrical HEX from my Reatta and now all that remains is pure driving Enchantment ...<P>Thanks Again from the "Family Moron"<BR>bob p