Here ya go:
Service Bulletin 03-072

CUSTOMER INFORMATION: The information in this bulletin is intended for
use only by skilled technicians who have the proper tools, equipment,
and training to correctly and safely maintain your vehicle. These
procedures should not be attempted by “do-it-yourselfers,” and you
should not assume this bulletin applies to your vehicle, or that your
vehicle has the condition described. To determine whether this
information applies, contact an authorized Honda automobile dealer.
October 3, 2003

Applies To: 2003 Accord V6 – ALL
A/C, Cruise Control, A/T Shift Position Indicator Do Not Work (DTC
U0155)

SYMPTOM
The customer complains about at least one of these
intermittent symptoms:
• A/C doesn‘t work.
• Cruise control doesn‘t work.
• A/T shift position indicator in the instrument cluster doesn‘t work.
NOTE: When this problem occurs, all of these symptoms are present, but
the customer may not notice them all.

PROBABLE CAUSE
A communication problem between the F-CAN (controller area network) and
the Powertrain Control Module (PCM).

CORRECTIVE ACTION
Use the Honda Interface Module (HIM) to update the PCM.

I don't think you can fix this yourself; it's a software problem, and
only the dealer will have the update.

--Gene