First CEL - P0500 (1 Viewer)

[Trunk Monkey]

Well, my beloved 100 finally coughed up it's first CEL - a P0500, vehicle speed sensor. The speedo is still working and I'm getting speed on my Scangauge, so that means it's in the wiring somewhere between the cluster and the ECM. Somewhere.

Cruise isn't working either. Bah.

 

[boombapslappy]

Have fun with that. I generally don't have the patience for electrical problems. Hope it works out quickly for you.

 

[Jrod]

Just because you're getting speed at the cluster doesn't mean the sensor isn't bad. Pull it from the diff and replace it. That's likely your problem.

 

[Trunk Monkey]

Diff? You mean t-case? Why would I still be getting speed at the ECM and speedo if the sensor was bad?

 

[Jrod]

Wherever the speed sensor is located. I've replaced faulty one's in cars and they are always in the diff. The sensor can be going bad and you still get speed at the cluster.

 

[OregonLC]

does the ECU perhaps do a comparison between VSS and ABS sensors? In fact, I would think that everything it needs to know could come from the 4-channel ABS pickups. wonder why they use both?

 

[sleeoffroad]

There are two speed sensors. SP1 and SP2. One is located on the transmission and one is located on the transfer case. Transfer case one goes to instrument cluster then to ECU. In case of failure of a speed sensors, the ECU will use the other one, so you will still see speed on the scan tool. You need to figure out if SP1 or SP2 is the culprit. There are procedures where you can hook a scope to the pins at the ECU to verify that you are getting the signals.

 

[OregonLC]

^ this!

Gotta love having experts around! Makes MUD great!

 

[Trunk Monkey]

Just an update, hooked up a scope to the ECM, the voltage from the VSS was only about a volt and should be between 4-6 volts. Chased it backwards to the speedo. The cluster has an amplifier that takes the signal from the VSS, amplifies it to the proper voltage for the ECM and converts it from an analog signal to digital. The voltage at the cluster was still only about a volt. So, looks like it's a bad signal amplifier. Just the board is $250 new, I'm trying to locate a used cluster to pull one from to swap into mine.

 

[jgray]

Trunk - You might want to give these guys a call. They are in my hometown and have a 98 that was picked up durning cash for clunkers trade in. I'm not sure what is still left but I still show he has parts available. If I can help with shipping or anything just let me know.
Joe's Auto Parts

 

[2000UZJ]

Trunk - You might want to give these guys a call. They are in my hometown and have a 98 that was picked up durning cash for clunkers trade in. I'm not sure what is still left but I still show he has parts available. If I can help with shipping or anything just let me know.
Joe's Auto Parts

I hope the headunit is still in there. I need one as of today

 

[Sowbug2000]

Trunk,

I have the same error message right now. I'm not familiar with this. Is the VSS critical? How much do you think it would cost a dealer to fix it if its broken?

Thanks for your thoughts!

Derek

 

[Trunk Monkey]

Depends on what's causing your code in the VSS system. Is your cruise control working? Most dealerships would probably start with replacing the VSS ($200 + labor) and if that didn't solve it, then maybe if you've got a good tech they'd go into the speedo (circuit board $250 + labor). Oddly the FSM is more vague, it calls for testing the VSS voltage at the ECM and if the voltage is bad it says to replace the ECM ($$$$$).

 

[Sowbug2000]

Sorry for the late reply! I tried the cruise the other day and it didn't work. The light came on but I couldn't get the cruise on. I'll give it another go, but....what would you do from here? Is there a way to check the VSS? What about the voltage on the ECM....where is it located and how volts is it supposed to be putting out. Anyone in Memphis have experience with this stuff? I would appreciate any help, and would pay for it too!

Thanks for any advice, Trunk!

 

[Trunk Monkey]

Well, I put in the replacement cluster and it didn't solve the problem. I have a VSS on order and will be replacing that when it comes in. My tech friend talked with a few others and they all diagnosed it as a bad amplifier in the cluster, but it doesn't appear to be the issue. Will report back with the new sensor.

 

[rking]

Where did you get the replacement cluster, and was it a straight swap as in a 99 for a 99? I'm thinking I may want to update mine to a 05+ and was hoping that was possible.

Sent from my iPhone using IH8MUD

 

[Trunk Monkey]

No idea, mine was same style. I was swapping circuit boards for the amplifier. Besides, swapping out like that screws up the odometer and that's a big time no-no.

 

[Sowbug2000]

Any update Trunk? I am going to take mine to the....ahem, Stealership this week......uggggh.

 

[Trunk Monkey]

VSS that came in was the wrong one. So, I swapped in a known good one from another 100 and it didn't clear the CEL. Talked with my tech friend and he thinks it's in the harness - either VSS to cluster or cluster to ECM. That will be a hoot to chase down. I'm also running by our local dealership to talk with a guy there that's one of the highest certified Toyota tech's in the country and get his take on it.

Careful taking your truck in, they may start throwing expensive parts at the problem without chasing down the root cause.

Why couldn't this have just been a coil pack?

 

[Sowbug2000]

VSS that came in was the wrong one. So, I swapped in a known good one from another 100 and it didn't clear the CEL. Talked with my tech friend and he thinks it's in the harness - either VSS to cluster or cluster to ECM. That will be a hoot to chase down. I'm also running by our local dealership to talk with a guy there that's one of the highest certified Toyota tech's in the country and get his take on it.

Careful taking your truck in, they may start throwing expensive parts at the problem without chasing down the root cause.

Why couldn't this have just been a coil pack?

Great!! The problem is....I don't know sheet about it. I'm sure they'll throw the most expensive at me! I'm screwed.