Vehicle speed sensor problems

[S.hafsmo]

I've recently taken the car out of winter storage, and my first long trip has revealed some issues with the vehicle speed sensor. Intermittent loss of speedometer to begin with, but now it's mostly out all the time. This causes SES- and Service Ride Control lights, also loss of secondaries.

I'll get under the car today to check the sensor/connectors/wires, but are there any other known issues with this system?

I'm guessing the sensor is a MY 90 spesific, no longer available, and the later version uses a different signal?

[S.hafsmo]

Removed the sensor, and got a bit surprised by it being below the oil level in the transmission (messy business). Just held a rag in the hole while visually inspecting the sensor. Looked fine.

The vss was working before I tinkered with it, but not after. Came back after a few miles.

An interesting thing worth noting, is that it starts to function if I put a bit of load on the engine. High gear/high speed. Could it be that the twisting motion of the engine moves the wiring loom in such a way that a poor connection gets temporarily fixed? I haven't had time to check the loom yet.

[Demps]

Good info here:

http://www.zr1.net/forum/showthread....light=Vss+gear

Ted

[S.hafsmo]

Thanks Demps, I've read that one. At least my gear is still in place. Wondering if I tugged the harness when I had the tranny out. Does the harness go straight to the ECM?

It seems the vss function is not load related, but speed. Above 50mph it usually pops back into life. Can I assume it generates higher voltage at higher speed?

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[-=Jeff=-]

FYI, the later 91-95 VSS should work fine, you just need to change the connector on the harness..

[S.hafsmo]

Thanks Jeff. Are these still available? If the rear of the car is on ramps, should the sensor be above oil level?

[S.hafsmo]

Did some testing today, but I'm still left puzzled. There's no clip on the gear on these, yes?

VSS gives voltage depending on rotating speed, but as I don't have any comparison, I don't know how what voltage it should give at low speeds. Seems slightly unstable at slow rotational speed. 1.5V AC / 480 RPM.

Checked continuity of the cable by jumping the end terminal and measuring at the sensor connector. Yellow/purple cable. Shows 0 Ohm.

Still no result after re-connecting. IMG_20190602_112158.jpegIMG_20190602_113450.jpegIMG_20190602_113500.jpegIMG_20190602_113517.jpegIMG_20190602_112302.jpeg

[S.hafsmo]

Don't know why the pics show twise. Uploaded through the app.

Edit, seems fine now.

[randy ransome]

I have a 95 ZR-1, the speedometer and odometer quit working. I bought a new VSS at NAPA Friday. It's made in America and appears to have the same markings as the original. Installed it Friday afternoon and drove to a car show. About 150 miles round trip. It worked Great all the way and I won #1 place in my class.

[HAWAIIZR-1]

Originally Posted by randy ransome

I have a 95 ZR-1, the speedometer and odometer quit working. I bought a new VSS at NAPA Friday. It's made in America and appears to have the same markings as the original. Installed it Friday afternoon and drove to a car show. About 150 miles round trip. It worked Great all the way and I won #1 place in my class.

Hey Randy,
Congratulations!!
Do you mind sharing the Napa part # that works for a 95? When I researched it at RockAuto it shows a few different part numbers. I’m in the US right now and will get a Napa part if so. Thanks!

IMG_4480.JPG


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