Honda ACCORD HYBRID 2005 Service Manual page 809

DTC U1221 (35): Motor Control Module
(MCM) Lost Communication with DC-DC
Converter
1. Turn the Ignition switch ON (II).
2. Reset the M C M (see page 12-6).
3. Check for T e m p o r a r y DTCs or DTCs w i t h the HDS.
Is DTC U1221 indicated?
Y E S — G o t o step 4.
NO—Intermittent failure, system is OK at this t i m e .
Check for poor connections or loose terminals at
the DC-DC converter and the M C M . •
4. Check the under-hood fuse/relay box terminal
(ORN wire) connection.
Is the connection OK?
Y E S — G o t o step 5.
NO—Repair connection in the w i r e t e r m i n a l , then
go to step 18.
5. Turn the ignition switch OFF.
6. Turn the battery module switch OFF (see page 12-4).
7. Remove the IPU lid (see page 12-140).
8. Check the + B connector (A) on the DC-DC
converter.
Is + B connector OK?
Y E S — G o t o step 9.
NO—Repair the + B connector (A) on the DC-DC
converter as necessary, then go to step 20.
9. Disconnect the DC-DC converter 4P connector.
10. Turn the ignition switch ON (II).
11. Measure voltage between DC-DC converter 4P
connector terminal No. 4 and b o d y g r o u n d .
DC-DC C O N V E R T E R 4P C O N N E C T O R
P-I—
2
i -
3
4
IIG1 (BLK/ORIM)
®
T e r m i n a l side of male t e r m i n a l s
Is there battery voltage?
Y E S — G o t o step 12.
N O -
• Repair open in the w i r e between the DC-DC
converter and the No. 18 ACG (15 A) fuse in the
under-dash fuse/relay box, then go to step 20.
• Replace the No. 18 ACG (15 A) fuse.
12. Turn the ignition switch OFF.
13. Disconnect M C M connector B (24P).
(cont'd)
12-131