Where is the lean angle sensor located on the Yamaha R15

if its the original chain you may not find a joining link. You will need to use a chain breaker to push a pin out, or out with the angle grinder to take the head of a pin, then use a pin punch.
The new chain will have a joining link, but it takes some effort to fit the side plate which is a press fit.

Yamaha YZF-R15 on Road Prices in India

• Yamaha YZF-R15 Price in Delhi/Gurgaon/Noida - 1,03,000/-
• Yamaha YZF-R15 Price in Bangalore/karnataka - 1,11,500/-
• Yamaha YZF-R15 Price in Hyderabad/Andhra Pradesh - 1,09,725/-
• Yamaha YZF-R15 Price in Chennai/Tamilnadu - 1,10,000/-
• Yamaha YZF-R15 Price in Mumbai - 1,12,725/-
• Yamaha YZF-R15 Price in Pune/Maharashtra - 1,09,975/-
• Yamaha YZF-R15 Price in Kolkata/West Bengal - 1,10,100/-

Yamaha has announced the price for the YZF- R15 today, and its going to cost Rs 97,425 ex-showroom price all over India.

More details on the R15 can be found here-

http://turbocharged.wordpress.com/2008/06/12/yamaha-r15-launched-specifications-details/

Source:http://economictimes.indiatimes.com/News/News_By_Industry/Auto/Two-wheelers/Yamaha_launches_150_cc_sports_bike/articleshow/3123551.cms

Hope this help ;-)

It means there is an incorrect message from the lean angle sensor.
"Code 30 = Lean angle sensor Latch up detected.
No normal signal is received from the lean angle sensor".
Engine management problem I would say or the sensor that fits under the subframe is perhaps faulty or upside down?
Hope this helps.