I have read may threads on the following subject but can not figure out what is the problem.

My 1994 E320 no longer delays it's trans shift from 2nd to 3rd when engine is cold as it once did. The engine light came on,: The code is #26 - Shift Delay Switch.

1. The Shift Delay Switch behind the master cylinder holds vacuum only from one side of the switch. Is this normal, or should it hold vac from both sides.

2. The Green vac hose going to the trans holds about 5 in on the gage max. Sometimes it will not hold any vac. I can try a second later, and it hold 5 in Hg again. Is this normal?

3. Could the problem be electrical?

I am just guessing here and could use some help. WHAT SHOULD I CHECK NEXT??

Much Thanks, John