BR/BD 100/250 R BP / RI
Troubleshooting
Page 141 / 171
Service Manual 08.2007
6.2.4 Head CPU (A1) error messages
Module involved:
Head CPU (A1)
Module clone:
There is only this bus master
Display code:
F1/xxx for faults/warnings of head CPU
Module
Fault
classification
Display code
Action
Head CPU
Actuator main
relay (K1) short
circuited
K1/021
1. Verify that the main relay coil (K1) is connected to
A1/X11-3 and A1/X11-4.
2. Check that fault voltages, for example, are con-
nected to the chassis that is short circuited
against battery voltage (supply line) via contact
closure and eliminate these.
3. If fault remains, replace A1.
Errors in multi-
secured parame-
ter memory
K1/101
1. Perform key switch (S0) reset.
2. If fault remains, replace A1.
No module
detected in bus.
Bus is mal-
functioning
K1/111
1. Check if bus plugs A1/X3 and A1/X4 are connec-
ted.
2. Check if bus lines A1/X3-2 after A1/X4-2 AND
A1/X3-5 after A1/X4-5 are completely connected.
3. Search for errors in lines No. 2 and No. 5 of all
bus cables and repair.
4. Test single module coupling, connect head CPU
(A1) with only one random module as direct bus.
If error is replaced by another, test with other
modules until the malfunctioning module is found.
Replace the malfunctioning module.
5. If fault remains, replace A1.
BUS ATTN
– is missing du-
ring self-test
– failed during
operation
K1/112
1. Check if bus plugs A1/X3 and A1/X4 are connec-
ted.
2. Check if the bus plug is properly connected to all
modules.
3. Search for errors in line No. 6 of all bus cables/
repair.
4. Test single module coupling, connect head CPU
(A1) with only one random module as direct bus.
If error is replaced by another, test with other
modules until the malfunctioning module is found.
Replace the malfunctioning module.
5. If fault remains, replace A1.
