022-906-041A VW Cylinder Head Temperature Sensor - Type 1, 2, 3 & 4

Cylinder Head Temperature Sensor – 022-906-041A (311-906-041A)

The 022-906-041A (also referenced as 311-906-041A) is a critical electronic sensor used in Volkswagen and Porsche air-cooled engines equipped with fuel injection (D-Jetronic or L-Jetronic). This sensor is threaded directly into the cylinder head and monitors the engine's operating temperature. The Engine Control Unit (ECU) uses this data to adjust the fuel-to-air mixture; when the engine is cold, the sensor tells the ECU to provide a richer mixture, much like a choke on a carburetor.

A failing 022-906-041A is one of the most common causes of poor engine performance in fuel-injected VWs. Symptoms of a bad sensor include difficult cold starts, a hunting idle, poor fuel economy, or the engine stalling once it reaches operating temperature. Replacing this sensor ensures your ECU receives the correct thermal data, restoring smooth drivability and protecting your engine from running too lean or too rich.

NOTE: This can also be used to an aftermarket gauge, as long as the gauge is matched tot he sensor.

Detailed Vehicle Compatibility

VW Bug (Beetle):

• 1975, 1976, 1977

VW Bus:

• 1974, 1975, 1976, 1977, 1978, 1979

VW Super Beetle:

• 1975, 1976, 1977, 1978, 1979

VW Type 3:

• 1968, 1969, 1970, 1971, 1972, 1973

VW 411:

• 1969, 1970, 1971, 1972

VW 412:

• 1973, 1974

VW Vanagon (Air-Cooled):

• 1980, 1981, 1982, 1983

Porsche 914:

• 1970, 1971, 1972, 1973, 1974, 1975, 1976

Product Highlights & Features

• Fuel Mixture Regulation: Communicates engine temperature directly to the ECU to manage the cold-start enrichment cycle and warm-running fuel curve.

• Precision Resistance: Calibrated to specific Ohms ratings that match original Bosch fuel injection requirements for accurate signal delivery.

• Direct Replacement: Features the correct thread pitch and electrical connector for a seamless "plug and play" installation into original cylinder heads.

Technical Specifications

• Part Number: 022-906-041A / 311-906-041A

• Sensor Type: NTC (Negative Temperature Coefficient)

• Application: Cylinder Head Temperature (CHT) Sensor

Installation & Maintenance Tips

• Avoid Over-Torqueing: The sensor threads into the aluminum cylinder head. Use caution during installation; over-tightening can strip the head threads, requiring a time-consuming repair.

• Check the Lead Wire: Often, the sensor itself is fine, but the wire leading to it has become brittle and cracked near the engine tinware. Inspect the insulation and the connector for corrosion or breaks.

• Test Before Install: You can test the sensor using a multimeter. Measure the resistance when cold and then again as it warms up; you should see a smooth change in Ohms as the temperature rises.

• Clean the Surface: Ensure the area around the sensor hole is free of debris before removing the old unit so that no dirt falls into the engine or interferes with the new sensor's seating.

022906041A

311906041A