My speedometer stopped working. It has intermittently came back but when I saw it come back on, it was not registering actual speed and dropped out again. I investigated the cluster. It seems to be ok. There was an older thread about a bad solder joint but it's on a 99 model. The panels on the flex circuit are totally different than the 98 model which I have.

 

ODB2 shows speed sensor. Haven't checked that out yet. Any thoughts.

Can you see vehicle speed with a scanner while plugged into the OBD port? If ECU is seeing vehicle speed, it's more then likely an issue with the head. If the ECU isn't seeing vehicle speed, it's probably the vehicle speed sensor in the transmission. Granted it's a 98, I have seen a few speedo head failures but not as common as the 99, which I need to fix in mine....

Also, the cruise control is somehow linked to this circuit and also stopped working.

If you scroll down this LINK (be aware its PG-13 because of the background pics used), past the cluster info, it'll show the speedo sensor - VSS-  IN THE TRANS that is not too hard to replace.  I'd pull it out and check the blade on the end - they break.

GL,

Td

Edited March 29, 201610 yr by wtdash

Is the speedometer and RPM on the instrument cluster both controlled by the speed sensor? The RPM works, speedometer doesn't, no cruise control.

 

 

Swap cluster or speed sensor.

 

good chance it's the 1999 speedo issue. Previously swapped with one from a 99 or a bleed over part from 99 production. Google the solder joint wire repair.

 

Swap the instrument cluster with one that has the same mileage.

 

theyre super easy to replace.

 

Www.car-part.com

Like wtdash said, check the drive blade for the speed sensor on the trans. The blades can break and cause this. Usually it's because the sensor is old and the rotating core inside it is getting sticky. If the blade is broken replace the blade and the sensor.

 

Rpm and speedo get signals from two very different places. Not connected at all.

 

Cruise gets its speed signal from the same speed sensor on the trans that the speedo uses.