[ford 1443]

On my way home from Daytona Beach this weekend, driving down I-4, decided to set cruise, 150 mile trip. Cruise wouldn't turn on, tried several times, no go. After getting home I check codes on my Edge Evolution, it showed the po500 code - vehicle speed sensor error.

Well I went down to my local ford dealer and picked one up($36.00). The old one "looked" ok, but it was a cheap part. I replaced it anyway. I cleared the code, but it came back, and cruise still don't work. Truck runs and drives fine, no loss of power, trans shifts fine, speedometer works, just cruise don't work. My transmission fluid level is in the middle of the safe zone.

The wiring and harness looked and seemed to be in good shape. I didn't see any knicks or stressed points on wires or connector. I have returned the truck to stock on the programmer, but same results. Also the vehicle speed pid on my programmer shows 0 mph, even when traveling 60 mph.

Does anyone have any ideas on what might be going on here? Any info will be greatly appreciated.

Thanks, Ron

 

[Mark Kovalsky]

Most likely it's a damaged wire to the speed sensor. Looking at the harness is almost useless. You need to test it, not look at it.

It is also possible that the tone ring in the differential is damaged. If the sensor doesn't see the tone ring you get the same result, no speed sensor input to the transmission.

 

[ford 1443]

Ok, where does the other end of the wires go ? Are they fairly easy to trace down? Check wires for continuity, resistance should read zero, right?

Tone gear, something you have to rip rear end to repair? I work for the next 9 nights straight. Will post back. Can driving the trunk this way do any damage? I need it to get to work.

Thanks, Ron

 

[Mark Kovalsky]

It probably won't hurt it to drive it like that.

Check for continuity from the sensor to the PCM near the driver's side battery. Don't push leads into the connector or you'll spread the pins guaranteeing a problem. Probe the backside of the connectors.

You need to remove the diff cover to see the tone ring.

 

[dieselmac]

Isn't the P0500 for the shaft speed sensor on the transmission?? I would think if the VSS on the differential went out it would set the ABS light since it's used for wheel speed by the ABS module.

 

[ford 1443]

Where is the shaft speed sensor located on tranny? I will check both wiring harness for vss and shaft speed sensor. Is there any way to test it? (shaft speed sensor)

As soon as my weekend comes up, I'll look into both. Any idea on price for tranny sensor? I really want to get this fixed, hopefully without the ford dealer. I had to jump on it pretty hard getting on I-4 this morning and it don't seem to have the pick up it used to.

As for the toner ring, do they fail very often?

Thanks for any info, will post back, Ron

 

[Mark Kovalsky]

There is a turbine speed sensor, and intermediate speed sensor, and an output speed sensor. All three are on top of the trans.

The output is at the rear, the intermediate is in the middle of the trans, and the turbine speed is near the front of the trans, just behind the bellhousing.

P0500 means vehicle speed, and that's the sensor on the rear axle.

 

[ford 1443]

I am going to check the vss harness I hope Thursday morning. Are the wire colors the same at the pcm as they are at connector? I was looking yesterday at drivers side where wires come up thru bottom of engine compartment, man, that's a lot of wires. Looks like it may plug into another harness, then into pcm?

Once wires are located do you check individual wires separate or do you put a jumper in between the the pins on one end and check continuity at the other?
Is it possible that the vss not being read could cause the truck to not get up and go? I notice this around 50 mph and up. When I go to work this afternoon I'm going to put boost on my programmer to see what it reads.

Thanks, Ron

 

[knightgang]

Wheel speed sensor (and there are four of them) willa affect the and system. It is either going to be a tranny sensor or the rear axle sensor. One provides info for the speedo, the other provides info to the PCM.

 

[ford 1443]

This morning before I left work, I unplugged the vss on rear diff. Before I got out of the parking lot the ABS light came on. I shut the truck off and plugged vss back in, ABS light went out. Does this mean that vss and harness are ok or is there more linked to the harness that could affect signal getting to pcm?

Just trying a couple of short checks before I have to go to bed in the morning, working night shift doesn't give me a lot of time during the day to do much of anything.

Thanks for any information, Ron

 

[ford 1443]

PO500 CODE UPDATE

Well got truck back from the dealer last night. It took them 3 days, but it's fixed. For some reason Ford (according to the dealer) ran VSS signal thru the windshield wiper motor and then to the PCM.:dunno: They said the printed circuit board on wiper motor shorted out, PCM not getting a signal. Sounds strange to me, but everything is working.:thumbsup:

Has anyone heard of this before? Just want to say thanks for the info I got from the forum.

Ron