Bosch SHU 4000 Diswasher timer not advancing P/N 264177

[markcm]

Our amazing bosch SHU4000 dishwasher which has provided us with thousands of washes over 20 years without missing a beat finally gave us our first issue. The timer stuck in several positions leaving the machine running for hours on end until we manually moved it forward.

The machine is absolutely amazing and we would love to keep it going. I am hoping to find a used working timer or a DIY to repair this one. If all else fails I see that ApplianceTimers dot com  (LINK) offers a repair service and I have used them before with good results. I'm pretty handy, good with mechanical and electrical and have done some other appliance DIY such as finding cold solder joints on our Thermador Timer and repairing it; I'm hoping to learn what the failure mode is in these timers and maybe repair it myself. 

From what I have found, the OE part number for this timer is 264177, interchangeable part numbers are reported as: 
467078
AP2804275
BSH 264177
PS1443427
PT8412825
AH3448278
EA3448278
PS3448278

Any tips are appreciated.

[stickerbush]

I'm aware this thread is 5 years old but I have something to add that may be helpful to someone down the road.

My 25 year old Bosch SHU 4036 was getting stuck and sometimes it would run for hours. I suspected the timer/control unit but inadvertently stumbled on what I believe was the problem. There is a thermostat, a small round disk, mounted to the outside of the door panel. The thermostat is held in place with a spring clip. The thermally conductive paste between the thermostat and the door panel had dried up and some had flaked off. I got some Arctic Silver thermal paste at Radio Shack (sold for use with computer CPUs and heat sinks) and remounted the thermostat with a dab of the thermal paste.

The DW has run through 2 test runs now without getting stuck. I'm not 100% convinced yet but I'm cautiosly optimistic that I've fixed the problem.