P1296 is the code im getting on my 2001 vw beetle. i already changed the coolant temp sensor, is the thermostat the way to go next?

not the pump but air in the system or a broken wire to the coolant level sensor
that sensor at the top of the radiator tank has to be completely immersed in coolant or the circuit is broken and the light comes on
same effect id the wire to that sensor is broken in the insulation

P1296 is a cooling system malfunction. The two things that will set this DTC is a defective Engine Coolant Temperature (ECT) sensor or the thermostat.

VW DTC 17704 (P1296) - Cooling system malfunction.

Coolant Temperature Sensor (CTS) is faulty and reading an incorrect temp'.

Replace with the new version of the sensor, clear the code.

If indicated coolant temp' is too low the thermostat is sticking open.

P1296 is a coolant system fault code. It could be the thermostat, or the coolant temp sensor.
Either the thermostat is stuck or the coolant temp sensor is bad.
The coolant temp sensors have a reputation for going bad.

its the coolant temp sensor located on the lower hose neck above the transmission . you only need a pair of needle nose pliers for removing the clip that hold it in. good luck.

Both of these codes indicate trouble with the signal from the coolant temperature sensor.

So either the sensor is bad. The thermostat is not working properly and the coolant temperature is truly way out. The wiring to the sensor is short or open. The computer is bad and it is manifesting itself through this fault.

Does the car warm up properly? If it runs hot, or takes forever to warm up, this indicates a problem with the thermostat.

If the car runs at the proper temperature the next thing to look at is the coolant temp sensor and wiring. Some resistance values for VWs are here:
http://forums.vwvortex.com/zerothread?id=4267675

You might also be interested in this recall if your car is below 100k miles:
http://forums.vwvortex.com/zerothread?id=3694323

P1296 Malfunction in Cooling System
To Properly diagnose this problem, you will need to retrieve freeze frame data from the vehicle. If the temp at the time was -40 then the coolant temp sensor is faulty, if the temp was around 78 C then the problem is the thermostat, and if the temp was high the problem could be the water pump. Freeze frame data required and expanded OBD II scanner to retrieve.

The two things that will set this DTC is a defective Engine Coolant Temperature (ECT) sensor or the thermostat. This would cause the symptoms you described to me.

Good luck and Merry Xmass

sounds like you need tyo replace the thermostat

If it's a 2.0L, then the coolant sensor would be an easy fix. It's between the Air box / engine (on top of the coolant flange on the end of the head). If you do that, you probably should do a thermostat. Usually it's recommended to replace the thermostat when you do a coolant temp sensor, but that's up to you.

t's a cooling system malfunction code. Either the car took too long to reach operating temp (like a stuck thermostat) or is getting bad readings from the temp sensor. It's the same unit as for the gauge but a different part sends a signal to the ECM, so the gauge ma read fine.It means more than likely your Coolant Temperature Sensor (CTS) is faulty and reading an incorrect temp.
As noted by a few above, replace with the new "green top" version of the sensor, clear the code, and you should be set.
You shouldn't need anything else unless the thermostat is sticking open...