We have a 2010 G37 with 50K miles. After raising or lowering the top all the way we were getting a "top in operation" message and the buzzer would sound even though the top was all the way up or down and the beeper had sounded. Dealer hooked up his scanner to the body control module and said it rear "low voltage" from one of the sensors. He reset it and a few weeks later did the same thing. Took it back, he reset it and a few days later did the same thing. A third time it happened and it was time to call Infiniti. The forth time they scanned the battery. It was reading 12.4 volts as it should. Fuse and relay fine. Tech noticed that the number on the battery (original in the car) was not listed on his scanner as being used in the G37. Some investigation revealed that this model battery was installed in some G37 convertibles by mistake. Since the battery was 4 years old, it had enough to start the car but not enough to keep the sensor from reading "low voltage". The proper battery was installed on warranty and all is now well, The car went off warranty in July but since this problem started in May, it was completely covered. Pretty cool!

Follow Up: It has been several weeks now and the top has been put down and up many times...no problems. New battery was the cure.

Daman, Thanks for the post and the detailed description. I will be looking out for this on my 2010 as well (46,000miles). The vert has been great so far (1yr/8,000 miles of ownership) and I hope she remains problem-free. This forum has been a great source of important info both pre and post-purchase.

Update.......since last year, I have been having these ongoing problems with the top being all the way down yet the dashboard says "top in operation" and if you drive it, the buzzer sounds loudly in your ear. As described in my first post, they thought they had it fixed. Over the summer, it has acted up again. The sensor in the top says "low voltage" and shuts down the top operation. So, here is what they did. They figured there was a current draw somewhere. They let the car sit for three days, and sure enough, the battery was almost dead. They charged the battery and put their scanning tool on it and found a 675MA draw from the GPS/radio head unit. They removed the fuses for this unit, let it sit another three days and when they put the fuses back in, the battery had not lost any charge. Infiniti USA authorized a replacement GPS/Radio head unit and it was installed the other day. So far, no issues. The car is off factory warranty but since this has been an ongoing problem, warranty covered the entire thing. A big shout out to Baker Motorcars Infiniti in Charleston, SC for all their efforts and providing us with a nice Q70 loaner car. It has now been to Baker 8 times for this problem. Even Infiniti USA had no idea what the problem was. The top guy at Baker who works on Mercedes, Porsche and Infiniti tops said he had seen the same problem in a Mercedes so he looked at the GPS/radio unit in my car and found the problem with a short in the system somewhere that was creating a draw, not enough to notice in a day but enough to set off the top low voltage sensor.

18 months later and no more top issues. Car running great.