I have a 08 IS250, and recently upgraded from iPhone 3GS to iPhone4. I have not had any issues connecting my 3GS to my Lexus Nav in the past, but after upgrading to the iPhone4, I get periodic difficulties re-pairing to my phone.

Normally, the car will automatically pair with the the phone once the engine is turned on but with the iPhone4 sometimes it seems like the bluetooth on the phone is frozen and my nav can't pair with it. I have to turn off the bluetooth on the phone and turn it back on to get it to connect. Anyone else have issues with bluetooth?

 

I'm not having any problems...

 

no problems ...same combination.

 

I have the same problem as OP. I also have the iPhone 4 (tried both iOS 4 and iOS 5, both have this issue). Like the OP, I have to turn off bluetooth and turn it back on whenever it doesn't want to connect to get it to connect.

Anyone find a resolution?

 

iphone 4 with ios5 user here, no problems at all. Try deleting your previous and current bluetooth phone thing on the navi and resync them see if that helps

 

Try resyncing it.

 

iPhone4 with zero issues. Honestly, in the 18 months I've owned the car, I don't think it has ever not sync'd up. Do you put it in the same pocket as your key? I've heard that could cause some issues.

I also have a bluetooth music gateway in the center console however about once a month it doesn't connect with that and I have to manually sync with it.

 

BLUETOOTH TROUBLESHOOTING:

How to set-up Bluetooth; With Navigation:

We’ll use an iPhone4 for ex. Go to
- Settings
- General
- Bluetooth
- make sure bluetooth is on (slide on/off)
- Below that is "Devices" or "search device"
- On the phone, select the "hands-free" 2009 below or “Car Multi Media” 2010+ under search device. It should begin paring and prompt you for the passkey. Enter it and select "pair". It may say it's paired but not connected. If this is the case, then select "hands-free" one more time.

From the car:
- Car on/acc mode
- Info
- Telephone
- Settings
- Register phone
- it'll bring up a menu that has a passkey and looks like it's ready to pair
- Pair

Just to double check that the phone is paired to the car, from info-telephone-settings-select phone. The phone should be in the system now with a little "BT" symbol next to it.

For Non Navigation Models:
Use the push to talk switch and the voice should layout some commands. One of which is "phone set-up". Say phone set-up and continue with the voice instructions by hitting the push to talk switch and saying "yes" "pair phone" etc... Meanwhile from the bluetooth menu in your phone (probably under settings, make sure the phone is set to "discoverable mode". Once the phone is searching, "Hands Free" should show up on your phone. Select the pair button and you should be prompted with a pass key (four digits + enter) it's usually 1111 or 1212 etc...

________
Other Troubleshoots:

UPDATE YOUR SMARTPHONES:
Make sure your smartphones are turned off every now and then. They are just like a computer and need to be updated. Sometimes if a phone misses an update, the result is the Bluetooth connection unpairing with the car.

With BlackBerry’s, the most common troubleshoot is to remove the battery from the phone, blow on it and turn the phone back on. Yes it’s a PITA because BB takes forever to load, but it typically works. If this doesn't work either, you can try repairing the phone:

MY PHONE HAS BEEN PAIRED BUT NOT WORKING:
If the phone is not working (but already paired), a common troubleshoot is the bluetooth on the phone could be turned off (happens on mine from time to time). Set the phone to discoverable mode and make sure the bluetooth is set to "on". You should see the bluetooth symbol somewhere on the phones top banner.