Troubleshooting Steps
Communication Issues - Checklist
Page 50 MDE-4318D Competitive Pump and CRIND (CPC) Hardware/Software Start-up and Service Manual · May 2010
What voltage is present on TP2 of the T19547 Distribution Board?
This must be between 4.75 and 5.25 VDC (regulated). If this voltage is not present (or out of
specifications), then the T19547 Distribution Board (or transformer) will have to be replaced.
What voltage is present when referencing TP3 on the T19547 Distribution
Board to Chassis?
Note: Test with field wiring at P106 and P107 disconnected.
This must read 0 VDC. If this voltage is not present (or out of specifications), then the T19547
Distribution Board (or transformer) will have to be replaced.
What voltage is present when referencing TP3 on the T19547 to TP3 on
the T20488 Distribution Board?
This must read 0 VDC. If this voltage is not present (or out of specifications), then disconnect
the expansion cable connecting the two boards (from P104 to P104) and obtain voltage
readings again.
Ensure that you power down the D-Box before you disconnect this cable to avoid
blowing the fuse.
CAUTION
If voltage is now 0 VDC, the R19262-G2 expansion cable may have to be replaced.
Note: If you cannot isolate the expansion cable as the reason for the fault, reconnect the cable
before you proceed.
If voltage is still present, then disconnect the field wiring connector at P106 and P107 and
obtain voltage readings again.
• If voltage is now 0 VDC, then stray voltage may have been introduced by a fueling
position. Isolate fueling positions individually and obtain voltage readings to locate the
suspected fueling position.
• If voltage is still present after removing field wiring, the T20488 Board will have to be
replaced.
What voltage is present on TP1 of the T20488 Distribution Board?
This must be approximately 13 VDC (unregulated). If this voltage is not present (or out of
specifications), then the T20488 Distribution Board (or transformer) will have to be replaced.
What voltage is present on TP2 of the T20488 Distribution Board?
This must be between 4.75 and 5.25 VDC (regulated). If this voltage is not present (or out of
specifications), then the T20488 Distribution Board (or transformer) will have to be replaced.