PearlGreenC4

Ok guys, I have a problem with my 1993 C4. Just the other day, I was driving, running about 50 MPH, and I looked down, and my speedometer said 0. I stopped and turned the car off, ate dinner, came bout out and started driving and it was working.

Yesterday, the same problem. Speedometer not working. Turned the car off and back on and started working.

Today, sat for 8 hours, I started it and got on to the road and noticed it was sitting at 0 MPH. I got to where I was going, shut the car off. Came back 5 minutes later, started, and still sitting at 0 MPH while driving.

Also, I noticed on the way home that my odometer isn't working during this drive, nor is my cruise control (I was on the interstate). Also, my fuel gauge is acting very funny. When I started the car, my range said 30 miles with 2-3 bars. Then when I stop, it will jump from 2 to 4 bars, and range will go up to 60. And vise versa when you accelerate. I know that I'm getting low on fuel and should be nearing a fill up soon, but at this point I'm not exactly sure how much fuel I actually have.

Also, my INST. MPG sits at 0 MPG while driving. All of my analog gauges appear to be working properly.

Please help. I have done some research but am not too sure where to start. My car does have 205,000 miles, and from doing research I see that it is some what common for soldering joints to become loose/disconnected behind the dashboard.

Thank you in advanced for reading my post and commenting!!!

WVZR-1

I wouldn't go chasing problems in the cluster first. I'd check the VSS connector at the transmission for a bad connector first.

I would then probably do some checking of the VSS. Is this an A4 or an M6 car?

A VSS is not particularly expensive for a '93 if it's got the lesser gear ratios. Do you know which rear axle ratio? On the SPIPD label in the console what are the 3 digit codes that start with a GXX or HXX?

VSS is on the left rear of the transmission and will have a 2 wire connector. Wires are generally PURPLE and YELLOW.

PearlGreenC4

I'm not exactly sure what the ratio is. Here's a picture:

WVZR-1

GOOD JOB - using the axle ratio GM1 (2.59) and also since you posted the SPID the VSS code D8K if you needed a VSS it's available using the GM# 10456091 as a reference at your auto parts store. If local doesn't work Amazon for a VSS47 should be correct and less expensive than maybe an eBay option.

I would doubt a VSS gear failure BUT the miles indicate that it's certainly a possibility. A 36 tooth GM# 25513043 for the driven and that's a more difficult find. If you were to find a drive gear failure that's a MAJOR replacement operation. Have you done drive-shaft u-joints yourself or had them done?

Do you do your own maintenance? Do you have a DMM (digital multi-meter)?

PearlGreenC4

Usually I do my own basic maintenance, oil changes, tire rotations, and other small minor things. There is no recent work done to the car that I'm aware of (I've only owned it for two months).

I do have a multimeter. So you say to start at the Vehicle Speed Sensor. How easy is it to remove that and test it/replace it? Is there a procedure in which to test it first before replacing?

Also, one other thing I forgot to mention. Ever since I purchased the car, every time I start the car for the first time and back out of my drive way, there will be a grinding noise coming from the rear (or so it sounds like), and the ASR Active Light will come on for a brief moment (probably 2-3 seconds) and then goes away.

About 2 weeks ago I also had an occurrence with the ASR/ABS system, where at a stop light my asr active light would come on and the car would idle rough, but only when your foot was on the brake at a complete stop.

I did some research and came to find that sometimes not having enough air in your tires may cause this, and topping off your brake fluid reservoir may help. That I did, and it didn't help much, as I still had that happen one time more after that and hasn't done it since. I'm told to check my wheels speed sensors, but at this point I'm not sure where to start.

Could this also affect my current problem with the speedometer? Now after putting the pieces together, it makes me think it may actually have to do with the wheel speed sensors. What are your thoughts?

WVZR-1

I doubt that you have an issue with the wheel-speed sensors that can be related to the MPH/ODO. The VSS could certainly create issues with the ASR/ABS and you could see DIC information. I'd concentrate on the VSS first.

An on the car VSS check would require that the rear wheels are off the ground SAFETLY and with your meter you could check the VSS for an AC not DC output. Very low voltage but AC, would increase with speed but it would NOT require higher speeds. If you had no VSS signal I'd remove the VSS and confirm the condition of the driven and drive gears ONLY because of your higher miles. If done on the ground SAFETLY would mean a minimum of two sets of stands, one for the car chassis for SAFETY and the second set to keep the wheel/tire off the ground. A proper lift I'd think maybe a wise choice, if you didn't have access to all the required stands (higher quality) then maybe a 'for hire' to check the VSS output, making sure it's done your way.

That would complete the test but I'd certainly first confirm and clean the connection to the VSS.

If you found a VSS local maybe you could arrange a purchase with return provisions if you didn't use it. LOCAL buys are great if you arrange in advance. They should understand. I'd buy an O-ring seal for the VSS so that maybe while on the lift if you elected to remove and check the drive/driven gears you could reassemble with no leaks. The VSS seal is a GM #15552872. The seal should be on most dealers shelves. No generic o-ring for this is suggested.

WVZR-1

Some things come to mind maybe for you to short cut the diagnostics. Your car has C68 so you should be able to display MPH from the AC panel. If you can display MPH from the C68 the VSS is working and the problem is likely cluster/LCD etc. BUT since you've got from time to time ABS/ASR my bets on the VSS.

This I think should work, hold the FAN "UP & "DWN" both at the same time for 5 seconds or so, and I believe the display should go to 00, press the FAN "UP" until 7 is displayed and then press the AUTO button. If that displays a MPH then the fault is NOT the VSS. I haven't used this function for 10 - 12 years but it should work.

You could also have a quality scanner attached to the ALDL and if speed is displayed then again it's not VSS.

If your Bose works do you have VSC?

I'm inclined to believe though that your issue is the VSS or the connection.

Here's a link that pretty much confirms what I've mentioned. I don't recall the -00 being "automatic" but it says so here

http://www.corvetteactioncenter.com/...codes-723.html

pkincy

Had a similar issue many moons ago. Local GM dealer with many stores across the country (now bankrupt) diagnosed about 5 total things they needed to fix totalling about $2500 to correct my problem. I thanked them, paid the $100 diagnostic fee and went home. Replaced 3 of the 5 parts they had diagnosed as bad......no help. I jacked the car up and pulled the VSS sensor cap which includes the VSS driven gear. Turns out my drive gear had walked about an inch on the tranny tail shaft. Put a big screwdriver in there and worked it back into position where it would drive the driven gear and 30,000 miles later it is still working just fine. So do jack up the car and pull that VSS connector and make sure both gears are good and are contacting each other.

Its free and the last time I changed the axle ratio and had to buy a new driven gear I think the retail cost was about $3.56. Likely a bit more now, but still cheap.

WVZR-1

OP - you would expect something positioned like this and anything other than would create what was intermittent but now none. There is a retention clip that holds that gear in place on the output shaft. If it's broken I believe it's replaceable without a major effort.

In this conversation there's a couple informative images. If the link works. I paid no attention to the conversation for validity.

http://www.justanswer.com/classic-ca...-pictures.html

PearlGreenC4

This information is gold. The car sat for about 3 days, I came outside to try this and of course the speedo just happened to be working. I did get my MPH to display on the climate control LCD. It was working and matched the same speed on my speedometer. I never knew about this, GM engineers are incredible.

I will try this again when my speedo goes out, and see if the MPH displays on the climate control LCD. If it doesn't, then I know to pull the vehicle speed sensor and test.

Thank you for all your help. I will keep you posted when I find something out.

WVZR-1

Clean the connector at the VSS and confirm the integrity of it, loose wire maybe.

PearlGreenC4

Ok, I have some news. I was driving today down the freeway at 75 mph with my cruse set. Then all of a sudden, the cruise disengages itself, and I look down and my speedometer says 0. I do the trick with the climate control module, and when set to option 7, it reads 00 as well.

Vehicle Speed Sensor?

How easy is it to get to and what all have to be removed to get to it? Some insight would be nice before I get it jacked up and start monkeying around under there.

WVZR-1

To only clean the connector, check and confirm the integrity of the connector you only need to lift the left side and use stands to "be safe" you unlatch the connector, clean with contact cleaner, alcohol or something of the sort, try to confirm the wires/terminals are securely in the connector shell, reattach, drop the car and drive off.

You need to remove no parts from the car, just unlatch the connector to the VSS and that will be obvious.

If you intend to do more I believe I covered that earlier for you regarding the what to buy and arrangements to make.

PearlGreenC4

Well, I cleaned the connector, but no luck. This is what it looked like:



I used qhd electronic connection cleaner. At one point during this, I mixed the can up with throttle body/air intake cleaner by accident. Could I have caused any damage?

The connection was very dirty, full of mud/oil/dirt/rocks. Thought this may help but I guess not. Maybe I damaged it when i used the throttle body/air intake cleaner by mistake?

WVZR-1

Did you release the connector and clean or just sprayed the mess that you found? You've got issues with some leaks but with the miles you mention it's not maybe unusual. I would be tempted to buy a new connector and install it, cut splice OR if you wanted maybe just buy the VSS, a new connector and take it apart. The retainer that holds the drive gear is inexpensive so maybe buy that just to have it in hand when you do take it apart. The retainer is GM# 6261781, less than $60 might buy everything except the gears if you found a failure with them. If you found a gear failure, put it back together until you found whichever failed if one did. I'm doubting that you'll find that.

Where ever you chose to buy the VSS they should also be able to help with the correct connector. I believe an H11 bulb uses the same connector style so if that were cheaper it should do. Try for fit before install.