Alright guys, got something for ya. Here's my problems and how I've tried to remedy it. Let me know if you have any ideas what the problem might be.

About two weeks ago, I was driving down the road and my speedometer starting dropping from 60mph (correct speed) to 0mph. It bounced several times before finally going out. My odometer and trip also stopped working. The next day my check engine light came on so I ran to AutoZone and their code scanner came up with a Vehicle Speed Sensor malfunction so I bought a new one (the one that's in the back of the transmission). Later that day before I got the new VSS put in, I needed to run into town so I hopped in the truck and got to the first stop sign about 1/2 mile down the road and it died as I was slowing down to the stop sign. I was probably going about 15mph when it died so I was almost to a stop. It started back up.. After that it ran fine with no problems and seemed just fine. Still no speedo/trip/odometer though. The next day I put in the VSS hoping to fix the problems, but I wasn't sure if the dying was related to the speedo problem or something else. I swapped out the VSS with the new one from AutoZone. Simple install, just one mounting bolt and plugged into the wire harness. I removed the battery cable to clear the code and also put some HEET in the gas tank to help incase I had drawn some moisture in the gas tank or something (it's been raining and snowing lately. Lots of moisture). I checked all the fuses under the hood and in the dash and only found one that was blown. It was only for the cigarette lighter but I put in a new one anyway. After the VSS install, I took it down the road but still no speedo/trip/odometer. Got to the same point as the last time it died, and it died again when slowing down to the stop sign. The check engine light came on again about 10 miles down the road.

Since then, still no speedo/trip/odometer. I still drive it daily. What I've observed is, the truck ONLY dies when the truck is still cold and slowing down to a stop sign (when I'm down to about 15mph). It starts right up and idles great when I first turn the truck on in the morning. No hesitation or anything. It would idle all day long if I allowed it to. But when I get about 1/2 mile or so and the truck is still cold and slow down at the stop sign, it almost always dies or comes very close (kind of shakes). It seems like when I'm slowing to the stop, the engine revs so low that it just dies. Like someone flicking a switch. All my lights and radio stay on and such. No other warning lights or anything come on other than my check engine light which is always on. But this only happens while it's cold. After that when it's warm, it's never dies and runs great.

So I'm at a loss. Let me know if you have any ideas at all. I have no idea if the speedo and dying problems are related, or just happening at the same time. The truck is a 1997 Ford Ranger 2.3L manual with 200,000 miles (actually stuck at 199,709 lol). I'm trying to get a few more months out of it before I get another vehicle. Never had any problems at all with it in the past other than the occasional brakes, starter, and timing belt. Thanks guys!

 

Try the fuel filter and if that doesn't work I hate to say this but it might be the fuel pump

 

Wholy cow I just realized you only 30 mins away from me. I live in Warsaw.

 

I will try the fuel filter. I've never changed it before so even if it's not the problem it's time for a new one anyway.

That's crazy we live so close. I actually work in Warsaw so I'm there basically every day.



Any other ideas guys (or gals) ?

 

I think the speedomiter is a whole nother ball game then the truck dying. Mine did the same thing and it did turn out to be the fuel pump. Pain in the butt but it fixed the issue... GL!

 

Ok I've been doing some more looking online and found some information online that I found very interesting. This is a cutout of the article.

"The Vehicle Speed Sensor (VSS) supplies this signal to the components that require vehicle speed information including the speed control amplifier for cruise control equipped vehicles and computer. The computer uses the VSS signal for emissions control programs and speed limiters. The emissions programming can cause a manual transmission vehicle to stall out while decelerating if no VSS is used."

So to me that is exactly what's wrong. What also I did notice is that the vehicle speed sensor that I received from AutoZone looks like this:



While the old one that came out looks like this with a gear on the end. I'm assuming maybe they gave me the wrong speed sensor? Maybe I need one with the gear on the end? :

 

Update.

Found out I need to put that little gear from the old VSS onto the new VSS. It was in perfect shape so that's what I did. Still same symptoms. Wiring looks ok. Think it could be a problem with the PCM?

 

I doubt it but it could be. But if you need any help fixing it I'm willing to lend a couple hands if you want.

 

Does the truck have ABS ?
Check the top front of the rear differential for another speed sensor as rockauto.com shows both the one on the trans and one on the rear diff.

 

OTRtech - Yes My truck does have ABS, but from what I gather, 95-97 Rangers use the VSS for speedometer and the ABS speed sensor for the ABS only. Also from what I gather, if the ABS is not working properly, my ABS light should stay on which it does not. I suppose I should take a resistance reading across that ABS sensor to see if it's reading correctly.

Did some tests today with a multimeter with some info I found online. Voltage to the VSS is good at 11.6V from the plug. The VSS itself is good with a resistance of 207 ohms across the terminals. What I did find wrong is, from the information I got, Voltage between pins 58 (vss+) and 103 (power ground) in the pcm wiring harness should be less than 1v when stationary and fluctuate up to 5v when rotating the drive wheels. Mine reads 11.6v all the time. I know I'm using the correct pins since they are the correct color going in and the pins are labeled. Seems I have some kind of short in the wiring or another module on the same circuit which is causing bad readings to the pcm. Sounds like a nightmare. Not sure even what other modules are on the same circuit as the VSS.

 

Check resistance of ABS sensor and it reads good at 1100 ohms. Also when I leave it disconnected, my ABS light stays on. When connected, it goes away so I'm confident the ABS sensor is not at fault.

 

Sounds like a broken connection , not a short , between the PCM and the sensor on the return side.
Check for a burnt wire hanging near the exhaust . Also check the seam where the bell housing meets the engine block. It's possible the transmission was once removed and when reinstalled a wire was pinched between them and finally broke off.

 

I will look for that when I get a chance. Hopefully tomorrow. I've had the truck since it had 73,000 and I don't think the tranny was ever removed.. atleast not as long as I've had it and I wouldnt think it would have needed anything like that before 73,000 miles but a broken connection is definitely a possibility. I found this wiring diagram online that should help my track this down. I can still drive the truck as is, but it's annoying me that I can't figure it out because I know it's something not real complicated... if I can just find the broken connection!

http://www.autolib.diakom.ru/CAR/For...RAMS/15630.pdf

I also have some more resistance checks that I can do hopefully tomorrow to try to pin point exactly which wire is open.

 

I believe the VSS sends an input signal to both the PCM and GEM via splice 111 and the GEM sends output signal to speedometer.

 

I will have to look into that also. Would a schematic show this? I can't remember seeing that in the schematic, but I might have missed it. Is the gem located behind the radio and to the left?

 

Also do you know where splice 111 is located?

 

After doing some more digging, and from what I was able to find online, the above is not correct.

From the wiring diagrams I was able to locate it appears the VSS sends a toggled signal via the Grey / Black stripe wire to PCM pin 58, GEM, and Speedometer via splice 111. The other wire, Pink with Orange stripe on the VSS goes to ground connection G104 (should be next to battery). See attached diagrams Diagram 1 Diagram 2

 

I guess that doesn't look too difficult if I can find the wire and splice locations. I think I might just be able to figure this out when I get time probably on Tuesday. Thanks so much for those wiring diagrams. They are a little better than the one I had. I know where G104 is located. It's by the battery, kind of near the front left wheel. Any guess where splice 111 might be? Think it's in the dash somewhere or closer to the VSS underneath the truck somewhere?

 

Well I did some continuity tests. I have continuity from:

Pin 33 (chassis ground) to where it actually grounds
Pin 33 to VSS- plug
Pin 58 to VSS+ plug
VSS+ plug to GEM plug

So it looks like all the wiring is fine to me barring the VSS+ to speedo (don't want to mess with the instrument cluster). So I think I'm just prepared to just live with it. It hasn't died in a few days so maybe that's done with. I dont want to spend the money buying a new GEM, PCM, or instrument cluster just to see if it MAYBE solves the problem, nor am I willing to spend the big money for a dealership to figure it out. I guess it could be the meshing VSS gear inside the tranny is shot or the VSS plug not making good contact when plugged into the VSS itself. Oh well, thanks everything for the help.

 

With the VSS sensor, PCM, and GEM unplugged did you check for continuity between the gray and black stripe wire and and chassis ground?

If that checks good you'll need to verify your getting a pulsed signal from the VSS sensor with the wheels turning. Using your DVM you can tap the gray with black stripe wire at the GEM connector and drive around the block. Or you could put the rear end safely up on a set of jack stands and tap the wire directly at the VSS and or where it goes to the PCM.

 

So there SHOULD or SHOULD NOT be continuity from the grey/black wire to chassis ground? How would it be connected to the ground if all those were unplugged? Or should it NOT be grounded? Sorry I have only basic knowledge of electrical stuff.

The GEM connector is easy to get to so I'll test for a pulsed signal there while going down the road. From another site, I saw that voltage should fluctuate from 1v to 5v while the tires are rotating?

 

There should not be continuity between the gray and black stripe wire and and chassis ground

You'll want to leave the GEM plugged in. Just back probe the gray and black stripe wire.

 

When i swapped my trans i didn't hook the speedo up for two weeks because the sensors were different. You should not need to splice anything! The stalling is caused by the PCM not registering speed so it can't control the fuel correctly. It sees you revving to accelerate so it adds more fuel then when you slow down it can't "see" that your slowing down and never leans it back out so it basically floods itself out. If you keep running it it can blow the o2 sensor fuses thats what mine did it got so bad it would not stay running. It will also set a rich or lean code after a while thats what mine did. But just to answer your other question the speedo wires all go into the GEM behind the radio because thats what drives the speedo as well as other systems like ABS and traction control.

 

Were you ever able to figure out exactly what was wrong? I'm having the exact same problem and not looking forward to trouble shooting this in the dead of winter.