I have a mp5028 and it tells me 2 enter the code.

You will need a remote for this
Common Kenwood Security Codes
Many Kenwood radios are configured with the same security codes:

KCAR - This seems to be a "backdoor" to some Kenwood models.
3051 - This is the security code which is printed in the manual of many Kenwood models.
1234 - This is a security code commonly chosen by Kenwood owners.
Entering Your Kenwood Security Code
If the car battery fails or is disconnected, the Kenwood will ask for the security code.

The procedure to enter your security code differs on various models of Kenwood car stereos. Here are three of the more common procedures:

Type 1
During the code request mode, while holding the DISP key depressed, press and hold the Volume UP or DOWN key for 3 seconds until the "..." display disappears.
Enter the security code using your Kenwood remote.
Type 2
Press the "Auto" button and "Track up" on the face of radio at the same time until the four dash lines disappear.
Enter the security code using your Kenwood remote.
Type 3: Model# DPX-4020 and DPX-4030
Press and hold the 1 then the 6 preset keys until the display shows the letter 'C'.
Enter the security code using your Kenwood remote.
Entering Letters on your Kenwood Remote
To enter a letter using your Kenwood remote, press a button once for the first letter, twice for the second letter, and three times for the third letter -- then press the Track Up or Next Track key to send the letter.

To send the letter 'A', press the 2 key once and then press the Track Up key. To send the letter 'B', press the 2 key twice and then press the Track up key.

Finally, when you are done entering all of the letters, press and hold the Track Up button for 3 seconds.

The key sequence to enter the security code KCAR is:

5
5
Track Up
2
2
2
Track Up
2
Track Up
7
7
Track Up
Your Kenwood should then enter tuner mode.

A Security Code Bug in some Kenwoods
There is a reported bug in the security code handling of some Kenwood stereos. In models with thie bug, the security code is stored incorrectly. The workaround is to enter the wrong security code.

In models with this bug, you have to decrement the third character of the security code by one. If your security code was 1111, you would enter your security code as 1101. If your security code was 9999, you would enter 9989.