94 Cav. 2.2 mpi My speedo does not work

Here's another question for the Cav. Gurus...My speedo doesn't work. The needle is pegged at 100. Car has the automatic. Does anybody know the particulars about the speed sensor? Does it affect the way the trans shifts, at all...as well as the speedo function. Could it be something wrong in the ECM? The book shows which two connectors to short in the plug for the error codes, down there by your left knee, but when I did this, It did nothing...So cant even get the codes...Is my ECM fried maybe?

I am beginning to think that the tell-tale sign here is the fact that the speedo is pegged at 100+, and stays that way, without the sensor hooked up or with the battery disconnected. Seems not right...dont they usually sit about 15 mph, disconnected? I think the cluster is bad...anyone?///

When my 92 overheated last week I had to shut it down at 90. I let it cool down and when I started it back up my speedo was at 110. I pulled out and somewhere around 50 it dropped back down and has been fine since. Have you tried driving it over 50-60?

Yeah, I've driven it at highway speeds.

Yeah, I've driven it at highway speeds.
sounds like the internals have messed.

You say it doesn't work, has it ever worked or did it just happen?

You say it doesn't work, has it ever worked or did it just happen?

Well, the car was given to me a month or so ago, and it has never worked since I've owned it. It quit at 150K. Today, I tried a different instrument cluster, and the speedo does move, but very slightly...Like, it says 10 when I'm going about 40. I really hate to spend the 80 bucks for the speed sensor, but that MUST be the problem. I was going to check for an error code, but the book says not to start the car when checking for codes, and then it says that the car must be moving to get a proper reading for the VSS....HUH???? How do you do that? Push the damn thing? Not likely....Give me a good 'ol cable speedo...THAT I can diagnose...

The main drawback of cables, when they go they let you know. My wife had a 92 Ford Festiva, the speedo quit and days later it was making this outrageous deafning grinding noise, the faster we went the louder it got. Not to mention the smell of burning metal. We had to disconnect the cable from the block. Oh well, it's gone now, didn't want a Ford in my driveway anyway.

You tried a dif. cluster and it half-worked so why would it be the speed sensor? Maybe you got another bad cluster? Maybe it is the speed sensor, but like you originally asked does it have any affect on the shifting? If it did you would know by driving it. So I'm guessing the tranny has its own way of knowing when to shift. Not sure, I'm not a guru, (yet) so anyone else have any clues about what the speed sensor does?

Although possible, it seems pretty unlikely that I would have gotten another bad cluster. The trans. does not seem to go into 'torque converter lockup' at highway speeds, so maybe that sensor controls the TCC, as well...I dont know. Thing is, it all goes through the ECM...From what I understand, the computer rarely fails, and it seems that if it did, other bad stuff would be going on...but then again, maybe other Bad Stuff IS going on, that I havent discovered yet. I am going to order the VSS today, and will post my results..

Here's an update on my speedo sitch. I ordered the Speed Sensor, and when I went to get it, I find out it is totally different than the one in this car. Come to find out that someone has not only put an earlier model engine in my 94, but they also used the earlier model trans. as well. So, the REAL problem with my speedo, appears to be that The 90-91 speed sensor, is of course NOT going to work with my 94....totally different ECM, and other design differences between the two. At this point< I still think I can get the correct parts to make it work...Havent given up yet....Will update later

Here's an update on my speedo sitch. I ordered the Speed Sensor, and when I went to get it, I find out it is totally different than the one in this car. Come to find out that someone has not only put an earlier model engine in my 94, but they also used the earlier model trans. as well. So, the REAL problem with my speedo, appears to be that The 90-91 speed sensor, is of course NOT going to work with my 94....totally different ECM, and other design differences between the two. At this point< I still think I can get the correct parts to make it work...Havent given up yet....Will update later


Get a PCM from a 91 at a junkyard! Cheaper!

What the heck is a PCM?

What the heck is a PCM?
an ECM, ECU, VCM!!! Powertrain control module, Engine control module/unit, Vehicle control module! Although it was reffered as an ECM on 2nd gens by GM I'm used to PCM!!

Never heard it referred to as a PCM...Not too sure I would want to junkyard the box. The fuel injection system is from a 94, and to stick a box from a 91 in there...dont think that would work well. I may have to replace the governor, to get the speedo going, but hell...the car was given to me, and I only have about 300 bucks into it at this point.If I can make it a decent ride for 500 bones, then I'll still feel ok about the investment...Car is in decent condition, body and interior wise.

Never heard it referred to as a PCM...Not too sure I would want to junkyard the box. The fuel injection system is from a 94, and to stick a box from a 91 in there...dont think that would work well. I may have to replace the governor, to get the speedo going, but hell...the car was given to me, and I only have about 300 bucks into it at this point.If I can make it a decent ride for 500 bones, then I'll still feel ok about the investment...Car is in decent condition, body and interior wise.

sounds like someone realy messed that car up!!!!

sounds like someone realy messed that car up!!!!
Exactly how I feel!!! Instead of taking the hour (or less) to change the sensors from the old engine to the 'new' engine, they just threw it in the car...Surprised it ran at all...Fortunately, I am hoping that this VSS will be the last expensive thing...probably have to do the 'knock' sensor, and the coolant temp sensor to make it right...hmmmm wonder what else...maybe the TSS...maybe it just aint worth all the damn trouble...crap!

Exactly how I feel!!! Instead of taking the hour (or less) to change the sensors from the old engine to the 'new' engine, they just threw it in the car...Surprised it ran at all...Fortunately, I am hoping that this VSS will be the last expensive thing...probably have to do the 'knock' sensor, and the coolant temp sensor to make it right...hmmmm wonder what else...maybe the TSS...maybe it just aint worth all the damn trouble...crap!

probably not. Take the CEL bulb out and sell the car!

Well, I finally found the time to head down to the junkyard, and found a speed sensor for 15 bucks...score!! Now the speedo works just fine, AND the automatic door locks kick down, around 5MPH...pretty cool. It looks like the VSS, for the 92, and the 93 work on the 94...Tranny seems to shift better, as well, but that could be my imagination...Thanks for the input, folks...ONWARD!!!!!