Speedometer shows zero
Thread Starter
7th Gear
Joined: Mar 2007
Posts: 7
Likes: 0
Speedometer shows zero
Greetings,
I have a 1990 L98, c. 60k miles
Lately the speedometer is stuck on 0 mph while cold. Sometimes the car will stall when I make it a block away from the house and after restarting the car and getting up to 50-60mph the speedometer will start working. I have noticed the car will now start to drop MPH while running where it had not done that before.
Anyone have the same problem and fixed it? Is it the speedo sender at the transmission or the CPU.
Any help would be appreciated. I have not hooked up a scanner but will this weekend.
Thanks
-Tommy
I have a 1990 L98, c. 60k miles
Lately the speedometer is stuck on 0 mph while cold. Sometimes the car will stall when I make it a block away from the house and after restarting the car and getting up to 50-60mph the speedometer will start working. I have noticed the car will now start to drop MPH while running where it had not done that before.
Anyone have the same problem and fixed it? Is it the speedo sender at the transmission or the CPU.
Any help would be appreciated. I have not hooked up a scanner but will this weekend.
Thanks
-Tommy
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Speedo signal is from the VSS mounted in the trans tailshaft.ECM also uses this signal for it's calcs.
( ECM will run without VSS signal but believe it keeps the engine running when throttle closed on decel)
As it appears to come right when warmed up, possibly VSS is worn and jamming when cold or you have a problem with the drive gears
( ECM will run without VSS signal but believe it keeps the engine running when throttle closed on decel)
As it appears to come right when warmed up, possibly VSS is worn and jamming when cold or you have a problem with the drive gears
Race Director
Joined: Nov 2000
Posts: 17,103
Likes: 39
From: stop the fun suckers
I've had this issue on and off... It has been to the dealer twice and a tranny expert twice..
three VSS later.. it still had issues.. We replaced the gears, the output shaft and a bunch of other stuff.. finally tracked it down to a short in the oil pressure sensor circuit.. (tranny shop caught this one). check all your grounds and sensor wires under the car for brittle wires or shorts.. replace as req..
BTW: we also replaced all the O2 sensor pigtails, the VSS pigtail, the Oil sensor pigtail, and the parts of the starter wire circuit(oil coated),,
three VSS later.. it still had issues.. We replaced the gears, the output shaft and a bunch of other stuff.. finally tracked it down to a short in the oil pressure sensor circuit.. (tranny shop caught this one). check all your grounds and sensor wires under the car for brittle wires or shorts.. replace as req..
BTW: we also replaced all the O2 sensor pigtails, the VSS pigtail, the Oil sensor pigtail, and the parts of the starter wire circuit(oil coated),,
