AEG T56800 stops with 5 bleeps after 4min 30 secs..

Hello forum members,
I have been trying to diagnose what is up with this T56800 machine(AEG PN code 916 012 128). On a normal drying cycle, the machine will spin and warm up nicely but then after this 4.5 min period it will stop and bleep 5 times, pause and then bleep 5 times again (and so on).

Reading the forum, I tried to access the diagnostics by holding start+pause and clicking to position one. Diagnostics entered OK. On position 10, I get the start button flashing once with a simultaneous flash of the end led 5 times accompanied by the bleeping noise.

Not sure if this E15,E51 or should be read some other way as the error code. Any advice how to proceed further?