Error Code P1296 is defined as Engine Cooling System Malfunction. This refers to a problem in the coolant system, likely caused by clogs, overheating, or not enough coolant.

This error code I a manufacturer-specific trouble code, meaning it does not apply to all vehicles with OBD-II system or vehicles made since 1996 up to present. Rather, it applies to select vehicle makes, such as Audi and Volkswagen


As said earlier, Error Code P1296 means a problem in the engine’s cooling system, particularly the coolant temperature sensor. This sensor is found on the driver side of the engine, on the hose between the radiator and the block.

Common Symptoms

As with other error codes, this code activates the Check Engine light on the dashboard and registers the code. Other common symptoms include:

  • Cold start issues

Possible Causes

There are many possible caused for this code to appear. Some of the most common possible causes include:

  • Low coolant level
  • Defective Coolant Temperature Sensor
  • Open or shorted Coolant Temperature Sensor harness
  • Poor electrical connection in Coolant Temperature Sensor circuit

How to Check

Check the coolant level. If you have determined that there is not enough coolant, then refill it.

Get yourself a temperature sensor and O ring. They’re quite cheap.

For the 2.0 engine, the sensor is located along with the coolant line that comes from the top of the radiator and runs along the driver’s side of the engine. There’s a hose on the driver’s side that connects to a “junction box” which holds the sensor on top and facing the interior of the vehicle. There are our wires.

If the engine has been cold for at least one hour, pull the clip of the sensor towards you to remove it.

Remove the sensor by pulling it away from the hose. Then, seat a new O-ring on the new sensor and make sure it sits all the way at the top of the metal part of the sensor.

Insert the new sensor in the hose and then press it firmly downward, so it fits in the hole nicely. Replace the plastic lip below sensor on coolant hose.

Unplug the four (4) pin connector from the old sensor and plug it to the new sensor. You would know the pins line up correctly when you hear it click. Never force the pin into place.

Start the vehicle, check for leaks near and around the sensor, especially the hoses that you may have moved during the installation. In some cases, Check Engine light may be turned off on your vehicle. If not, then wait for a few minutes.

If the light is still on, then check the coolant temperature reservoir in the upper left-hand corner of the engine compartment. There are two pin sensor connections near the top, unplug the pin.

Start the vehicle after a few seconds (around 25 seconds). The red temperature light should flash, and the instrument cluster should beep. Turn off the engine and reconnect the coolant reservoir sensor connection. Then, restart the vehicle. The Check Engine light should disappear.

How to Fix

As with the diagnosis and repair suggestions above, the common fixes for this code is:

  • Refill with antifreeze or coolant
  • Replace coolant temperature sensor
  • Repair or replace open or shorted coolant temperature sensor harness
  • Repair or replace poor electrical connection in coolant temperature sensor

Other possible repairs include:

  • Check, repair or replace Coolant Temperature Sensor
  • Check, repair or replace Coolant Thermostat

In some cases, the code can be caused by a reservoir problem. Thus, you might also want to try unplugging the sensor before replacing the coolant hose.

This code is easy to diagnose and fix but can cause severe damage if left unaddressed for an extended period. Thus, it is important to have it fixed as soon as possible.

If you’re not confident on doing the diagnosis and repairs, then it’s better to ask for the help of a certified technician.