I have a 2000 Honda Odyssey with 92,000 miles.
My Odyssey rear brakes squeaks and check Engine Lamp came on for 2 weeks before I send my van in for service at McDavid Honda of Frisco, Texas. Just prior before that I had technician at Autozone help checked out my Odyssey van with a diagnostic tool and was told the service light came on because of a P0740 code.

At that time I do not know what P0740 code means.

Send car for 90,000 mile service at McDavid Honda of Frisco, Texas on the morning of Nov 16, 2006 with the Check Engine Lamp still on. Expecting issue to be diagnosed and necessary action taken to fix the problem.

Got a call to pick up the car later that afternoon and was told that everything checks out fine with the van except that the Battery was bad and its terminals are corroded and needs to be treated. Decline battery replacement and treatment because battery is still under warranty from Autozone.

Collected car and noted that the rear brakes still squeaks but check engine lamp is now off. Thought that check engine lamp problem was fixed. However two days later the check engine lamp came back on.
Called Service Adviser at McDavid Honda of Frisco and he denied ever having seen the check engine lamp lit when the car was sent in for service on Nov 16, 2006. He said that there would be a diagnostic fee to check the issue. Yikes!! just paid $382.48 for a major service and now he wants to charge a diagnostic fee for a problem that should have been detected in the first visit. Worked as an Engineer for 20 years, 12 of which were in the Quality Control Department and this incident stinks. Either the service adviser is outright blind or lied to me.

Sent van to Lute Riley Honda in Richardson to diagnose the issue.
Service adviser there confirmed that it was a Code P0740.