i need code help

I have a 99 dodge intrepid that will turn over but it wont start and its give me 2 codes 1 is p 1684 and 2 is p 1391 what codes are these what do they mean can someone help me out please thanks

P1684- Battery has been disconnected within the last 50 start-ups
P1391- Intermittent Loss of CMP or CKP sensor(s)

For more codes visit this site
http://autorepair.about.com/cs/troubleshooting/l/bl_obd_main.htm

Thanks alot for the help, How do I check the sensors and find out if they are good or bad and where are they located? Thanks.
And this would be the reason the car isnt starting?

Thanks alot for the help, How do I check the sensors and find out if they are good or bad and where are they located? Thanks.
And this would be the reason the car isnt starting?

Flip99,
Code 1391: No crank reference signal detected during engine cranking. Check the connector/circuit between the crankshaft position sensor and the PCM.

The crankshaft position sensor is mounted on the passenger side of the transmission bellhousing and is difficult to get to.
This sensor sends information to the PCM regarding engine crankshaft position. The sensor 'reads' the slots on the torque converter driveplate. The engine will not operate if the PCM does not receive a crankshaft position sensor input. The sensor determines both fuel and ignition timing. There are three wires in the sensor connector:
OR = 8V supply or reference voltage.
BK/LB= Sensor Ground
LB/DB= CKP Sensor Signal
To check the reference voltage from PCM disconnect the connector from the sensor, the Ign. Switch in the 'Run' position. With a digital VOM Probe the OR wire connection and the center connection (sensor ground) should read 8V. If this checks out good, you will have to proceed to checking out the sensor itself. Let me know, and I will step you through that process if you like.
Alvin

How do i take the clips off the sensor and how do i take out the sensors?

The sensor is mounted with bolts. Are you asking about how to take the connector off the sensor?
Alvin

Yes i am asking how to take the wires off the sensor and how many bolts are on the sensor and what size are the bolts?

Yes i am asking how to take the wires off the sensor and how many bolts are on the sensor and what size are the bolts?

To remove the harness connector from the sensor: Pinch the release and pull off. There are two specially machined bolts that control the space between the sensor and the flywheel. If you remove the sensor, be sure you use the same bolts.
Alvin

Thanks alot man for your help, how much of a pain is it to get to the sensor on the transmission and is there anything im going to have to take off to get to it?

Thanks alot man for your help, how much of a pain is it to get to the sensor on the transmission and is there anything im going to have to take off to get to it?

No nothing to remove to get to the sensor except the harness connector. It's a little bit of a tight place between the transmission and the floor above.
Alvin

Hey thanks alot man for your help, imma attempt to do it all tomarrow we will see how it goes.