Volvo 2001 C70 Trans codes p0740 and p1618.Aw55-50SN on 2001 Volvo C70

Trans has been rebuilt by pro with 40 years experience.
Codes and goes to limp mode every time I drive over 90 kms/per/hr.Simple reset restores trans.Smooth operation in all other areas. Scope shows SLU soliniod ingagement and holding threw range. Shows consistantly, a sharp movement in the SLT soliniod just before limp mode kicks in. Accurs only at speed.Seems to be getting a reduced duty cycle signal from the TCM suddenly at this point. SLT is Listed as Normally Open. Looking for help with the next step. Cheers

Asked by for the 2001 Volvo C70
Hi Rushy3

Magnus here from Stockholm.
I got the same problem that you had.

Did you find a solution for this problem? If so what do i need to do to fix this problem.

My car is a c70 year 2001 autogearbox with aprox 43000miles.

Thx Magnus Andersson Stockholm Sweden