speed sencor switch

[svt cobra brett]

Yes, the PCM tells the tranny when to shift based on a number of factors, and speed input is probably the most important. If the speedo isn't getting good data, chances are neither is the PCM.

Check the connection to the ABS computer which is located just forward of the battery tray. It's a 10mm bolt, and I recommend removing the connector and making sure both sides of it are clean -- it's very common for dirt and other contaminates to get into that connector. Usually a good blast of compressed air will clean both sides of the connector.

Short of that, as Ian mentioned it would probably come down to a problem with one of the ABS sensors. Have the codes scanned at AutoZone for free and see if there are any ABS codes.

ok i went and took out the batt tray and removed the connector and cleaned it real good on both sides with compressed air at our shop and put it back together and while i was there i cleand up all around the battery area and scrubed the tray and put it all back installed battery and cleaned the batt poast and cables and still i have the same problem.im going to the trans shop that a buddy of mine ownes and they will run the codes for free...so ill let you know what happend monday night

thanks brett

 

[Twisted99]

I had a problem with My 01 Lightning shifting weird and setting a tranny code for the vss. I changed the sensors in the tranny and the rear end..thought I had it covered. Nope, it was a couple of wires in the harness that had melted together. After I seperated and insulated I"ve never had a code set since. Might be worth a look..wiring that is.

 

[svt cobra brett]

Yes, the PCM tells the tranny when to shift based on a number of factors, and speed input is probably the most important. If the speedo isn't getting good data, chances are neither is the PCM.

Check the connection to the ABS computer which is located just forward of the battery tray. It's a 10mm bolt, and I recommend removing the connector and making sure both sides of it are clean -- it's very common for dirt and other contaminates to get into that connector. Usually a good blast of compressed air will clean both sides of the connector.

Short of that, as Ian mentioned it would probably come down to a problem with one of the ABS sensors. Have the codes scanned at AutoZone for free and see if there are any ABS codes.

ever heard of a turbin switch in the drivers side of the tranny...they had to r&r the axle to repl the switch...... abs codes came up clear

 

[Mr Anonymous]

ever heard of a turbin switch in the drivers side of the tranny...they had to r&r the axle to repl the switch...... abs codes came up clear

They are probably referring to the TSS "Turbine Speed Sensor". A bad TSS will definitely cause shifting issues, but I do not believe it is used at all in the vehicle speed input as I've left the TSS disconnected (inadvertently, of course) on a couple of tranny swaps I've done, and while the tranny shifts like crap, the speedometers always worked properly. To the best of my recollection, the axle does not need to be pulled to replace the TSS, but I'm not 100% sure on that, I'll have to look tomorrow.

If I have a chance I'll see if I can't review the TSS circuit to verify that there is no vehicle speed functionality.

My instinct would be to examine the ABS sensor rings for cracks first, then consider swapping the front ABS sensors with known good ones.

 

[svt cobra brett]

yea this has got me in a spin know???