HELP Fault found 00652 - Gear Monitoring 27-10 - Implausible Signal - Intermittent

I replaced the valve body on my 91 Passat auto due to a problem with the valve body .

The replacement is working except ( when in D ) when the tranny tries to shift from 3rd to 4th it slips then the following error is created

VAG-COM Version: Release 404.0-US

Control Module Part Number: 096 927 731 M Component and/or Version: DIGIMAT 0811 Software Coding: Diagnose VW Work Shop Code:

1 Fault Found: 00652 - Gear Monitoring 27-10 - Implausible Signal - Intermittent

Anyone know what is causing this .?

Ron Hoppe Ottawa, Canada