Limp mode/speedometer and odometer not working

SARAHELIZABETH85

MEMBER
1994 CHRYSLER LE BARON
3.0L
V6
2WD
AUTOMATIC
127,000 MILES

I recently purchased the car listed above GTC model, convertible. It is in limp mode, looks like it is stuck in second gear. The speedometer does not work and I recently noticed the odometer, at 127,000 when I purchased it, is now at 125,000. I have driven it maybe five miles tops. The mechanic I brought it to did not have an adapter to run diagnostics on an older car, so I took a gamble and replaced both the input and output speed sensors on my own. The speedometer still does not work. I did notice transmission fluid on one of the sensors I took out to replace. Is that indicative of anything? I read overfilling transmission fluid can leak out the sensors, I am not sure of what was done to the car before I purchased it though as far as that goes. I am waiting on a code reader to come in the mail. Until then, any suggestions on what might be causing these to fail and put the car in limp mode? And will the codes I eventually read be able to point to how to fix?
Thanks,
Sarah

1 Reply

CARADIODOC

MECHANIC
33,916 POSTS

Good news and bad news. Chrysler made reading the fault codes yourself much easier than any other manufacturer, but only codes in the Engine Computer, not the Transmission Computer. Cycle the ignition switch from "off" to "run" three times within five seconds without cranking the engine. Leave it in "run", then count the flashes of the Check Engine light. You will get a series of flashes for the first digit, a short pause, another series of flashes for the second digit, then a longer pause before the next code flashes out the same way. Ignore a code 12 if you get it, and code 55 just means it's done. On most models, if you think you miscounted, just turn the ignition switch off and back on once, and the sequence will repeat. You can go here:

https://www.2carpros.com/articles/retrieve-trouble-codes-for-chrysler-dodge-plymouth-odb1-1995-and-earlier-car-mini-van-and-light-trucks

to see the list of definitions, or you can post the code numbers in your reply and I will interpret them for you.

Most simple code readers do not access anything other than Engine Computers, but there are more and more of them coming on the market that will access Air Bag and Anti-Lock Brake Computers. A dandy alternative to the aftermarket readers is to look on eBay for a Chrysler DRB2. These were obsolete on 1996 and newer models, so you can find them for less than $100.00. Look for one that comes with a cartridge with a yellow "Supercartridge" label. Thati s a '94 cartridge that covers all models through 1995. Otherwise there were all kinds of individual cartridges for various models and years, and you have to be sure to have the right ones.

I have a DRB2 and I have a Monitor 4000. It was made by the same company that made the DRB2 for Chrysler, but it uses a different cartridge that covers Chrysler, GM, and Ford up through the year listed on the label. Mine also came with a separate cartridge just for Chrysler transmissions.

Now I have the newer Chrysler DRB3 for all of my vehicles. You can find those on eBay too. With an extra plug-in card, they could do emissions-related work on any brand of car sold in the U.S. starting with 1996 models, so a lot of independent shops bought them. Those too are obsolete now, so a lot of shops are happy to sell theirs to buy something newer.

All three of these I mentioned are full scanners, not simple code readers. In fact, reading diagnostic fault codes in numerous computers is just a small fraction of what they can do. Once you play with one of these, you will never be happy with a code reader again.