2003 deville has speedometer problems that are also causing transmission problems. Speedo works fine under acceleration but zeroes out when not accelerating. Has caused transmission to fail to pull but is apparently working now.

problem first showed up as a hard shift into forward or reverse. Added granny fluid to appropriate level. Any ideas. Fluid clean, no burnt smell.

2003 deville has speedometer problems that are also causing transmission problems. Speedo works fine under acceleration but zeroes out when not accelerating. Has caused transmission to fail to pull but is apparently working now. <br /><br />problem first showed up as a hard shift into forward or reverse. Added granny fluid to appropriate level. Any ideas. Fluid clean, no burnt smell.

Scan for codes. All modules and not a parts store reader.

Merged duplicate threads. Posts 1 and 3 of this thread came from the duplicate thread.

Please do not start multiple threads for the same issue.

Sounds like a bad VSS to me.

Agree. This is the next step. Reading live telemetry will be important here.

Thanks. Next stop a reputable shop.