how can i fix my diplomat adp8322 dishwasher?

hi, i have a diplomat adp8322 dishwasher, 3 wks ago i had a local repair man come and fit a new circulation pump/motor to my machine and it seemed to work ok for the first wash but then after sounded like the new part was revving to get machine to work, i dismissed it for a couple of washes as i thought the new part might just sound different, but then the next time i used it i put it on a 50 degree cycle and as the cycle was coming to a end it went into a error mode which was constant beeping and the rinse light on, and the following time it wouldnt even start this cylce and go straight into same error mode, i then for the next couple of washes tried different programmes which seemed to work on the 30 cycle, but then again after a few times on that would revert back to the error mode, this normally happens in the drying section of the cycle and the error code that keeps flashing is 4 flashes then a pause on the start button and the rinse button continously on, i hope you can make some sense of this, i have called the repair man back out who said he just reset the motor not looking at anything else, it worked for 1 wash but is now doing the same again. any advise appreciated