P113F

What P113F Means

Code P113F indicates a low signal level in the circuit for intake air temperature sensor No. 2. This sensor measures the temperature of the air entering the engine and sends that data to the engine control unit (DME). The DME uses it to adjust fuel-air mixture and ignition timing.

A low signal can come from a short in the wiring, a failed sensor, or a connector problem. With a short to ground, the sensor's signal line is pulled to ground, dropping voltage below the acceptable level. The DME then gets inaccurate intake air temperature data, which can affect how the engine runs.

Symptoms

• Poor engine operation (misfires, unstable rpm)
• Increased fuel consumption
• Possible power loss
• Hard cold-weather starting

Diagnosis and Repair

1. Read the fault codes with diagnostic equipment (ISTA, INPA) and confirm that code P113F is present.
2. Check the wiring and connector for intake air temperature sensor No. 2:

• Inspect the wire harness for damage, chafing, or corrosion.
• Check that the connector is fully seated and the contacts aren't oxidized.
• Test the circuit with a multimeter for a short to ground.

1. Check the sensor:

• Measure the sensor resistance at a known temperature and compare it to the reference values (see BMW technical documentation).
• If possible, check the sensor signal with an oscilloscope.

1. Replace the sensor if it's faulty. The part number depends on the model and engine — look it up in the ETK catalog.
2. Clear the codes and take a test drive to confirm the fault doesn't return.

Tools needed: diagnostic scanner (ISTA, INPA), multimeter, wiring repair kit.

Secondary Problems

Ignoring P113F can lead to the following:

• Running the engine for a long time on incorrect intake air temperature data causes an over-rich or over-lean fuel mixture, which leads to increased fuel consumption and fouled spark plugs.
• Over the long term, unburned fuel can damage the catalytic converter.
• Unstable engine operation can cause accelerated wear on cylinder and piston components.

Fix the fault as soon as possible to avoid more serious damage.