good morning i have a 2010 volvo V 50 traga EA880SR 1.-6 80KW TYPE MOT D4164T in the workshop

The vehicle was taken to the workshop with the wagon as it would not start

has the electronic key and inserting it into the ignition disengages the electronic lock, the ignition is switched on but does not start the engine

in the cdb I have the following messages antiskid service request and immobiliser retry start-up

the customer told me that it turned off in gear after 10 minutes and restarted and then did not start again

I have no communication with the engine control unit and have the following error codes

1A21 SIGNAL TOO LOW

DE11 COMMUNICATION DISTURBED 

DF433

if you have an engine management circuit diagram because from an initial test on the pins in the engine control unit I have no positive power supply 

and no under-key as the engine management relay is managed by the ecu with a negative

thank you