A TSB is a technical service bulletin and is not a recall as such so is not generally a compulsory thing. TSB's are for when a customer highlights a problem with there car and if a TSB exists for it Honda will deal with it.
It is not a recall and is not something that is usually in the public domain. hence why it is difficult to get any info on TSB's.
All manufacturers have them and are all equally secretive about them. Some dealers wont even know they exist unless they have carried out the work highlighted and some others will and be happy to share the info with you. I managed to obtain a copy of the TSB for headlight condensation from my local dealer after being told by 3 others that it didn't exist including the dealer who eventually found the TSB for me.
Here is the TSB for the VSA modulator.
TSB Bulletin No SK-07-007-00 dated 01-11-2010
This is only applicable to i-CTDI engines.
Models Affected
ACCORD 4D CN1 05, 06, 07, 08
ACCORD TOURER CN2 05, 06, 07, 08
CIVIC 5D EV1 05
CR-V RD8 05, 06
CR-V I-CTDI RD9 05, 06
Symptom
VSA light on, DTC 66-1 is stored.
Cause
Open circuit in the VSA modulator pressure sensor due to a production fault at the supplier.
Application: Warranty extension +3 years; mileage up to 62,000 miles
