E00

Explanation
During processing of an I/O request, execute channel
program (EXCP) processing encountered one of the following errors: A program check or machine check occurred while the input/output
supervisor (IOS) interruption response block (IRB) analysis modules
were processing or IOS POST was processing.
The operator pressed the RESTART key while the I/O request was
being processed.
A program check or machine check occurred while a nonresident
error recovery program (ERP) was processing or the ERP loader module
was processing.

System action
The system abnormally ends the current task. 
The system writes a logrec data set error record.  The previous error
record in the logrec data should indicate the cause of the abend.
The system does not provide the EXCP debugging area (XDBA).

System programmer response
Look at the messages in the logrec
data set error record for the probable cause of the error. If the
reason for the error cannot be determined or if an IBM-provided program
is causing the error, look at the messages in the job log for more
information. Search problem reporting data bases for a fix for the
problem. If no fix exists, contact the IBM® Support
Center. Provide the logrec data set error record, the JCL, the program
listing, and the assembly listing for the job.

Source
Execute channel program (EXCP)