Porsche 944 Reference Sensor Part Number: A Complete Guide

The Porsche 944 reference sensor is a critical component of the car’s Bosch DME fuel injection and ignition system. It works alongside the speed sensor to provide the engine control unit (ECU) with crankshaft position and RPM data. Without a functioning reference sensor, the engine may crank but fail to start, run poorly, or stall unexpectedly. Because these sensors wear out over time, replacement is common for 944 owners. However, finding the exact part number for your specific model year and engine can be confusing. This guide breaks down the correct Porsche 944 reference sensor part numbers, how to identify the right one, and what to consider when choosing a replacement.

What Is the Reference Sensor on a Porsche 944?

The reference sensor is a magnetic pickup mounted on the bellhousing, near the flywheel. It detects a single pin on the flywheel to determine engine speed and crankshaft position for ignition timing and fuel injection. There are two sensors on the 944: the reference sensor (gray connector) and the speed sensor (black connector). While the speed sensor reads multiple pins on the flywheel for RPM, the reference sensor provides the initial timing trigger. Early 944 models (1983–1985.5) use one type, while later models (1985.5–1988) and the 944 Turbo (951) may use different part numbers.

OEM Porsche 944 Reference Sensor Part Numbers

Porsche used several part numbers for the reference sensor over the production run. The most common OEM reference sensor part numbers include:

• 944 606 117 00 – Used on early 944 models (1983–1985.5) with the 2.5L 8-valve engine. This sensor has a gray plastic connector and a specific resistance range.
• 944 606 119 00 – Used on later 944 models (1985.5–1988) and some 944 Turbo (951) versions. It also has a gray connector but differs in internal resistance or wire length.
• 944 606 121 00 – Another variant for certain 944 S or 2.7L engines, particularly in the late 1980s.

It is important to note that the reference sensor and speed sensor look similar but are not interchangeable. Confirm the part number by checking the existing sensor’s tag or using your vehicle’s VIN.

How to Identify the Correct Reference Sensor for Your 944

Because the 944 went through several production changes, using the wrong sensor can cause no-start or drivability issues. Use these methods to ensure you get the right part.

Check by Model Year and Engine

The easiest way is to know your car’s model year and engine type. Early cars (1983–1985.5) use the 944 606 117 00 sensor. Late cars (1985.5–1988) with the 2.5L 8-valve use 944 606 119 00. The 944 S with the 2.5L 16-valve engine uses a different sensor (often 944 606 121 00). The 944 Turbo generally uses the late-style sensor but verify with your car’s production date.

Visual Inspection of Connector and Wiring

If you still have the old sensor, look at its connector shape and wire colors. The reference sensor typically has a gray connector and two wires (often black and white or black and yellow). The sensor body often has a stamped part number or a white label with the Porsche number. Clean the area to read it.

Using Your Vehicle Identification Number (VIN)

Contact a Porsche dealership or look up parts diagrams using your VIN. Many online parts catalogs (like Porsche’s own PET) allow you to enter the VIN to see the correct part numbers. This is the most reliable method, especially if you have a rare model or one that has been modified.

OEM vs Aftermarket Reference Sensors

When replacing the reference sensor, you can choose between OEM Porsche parts or aftermarket alternatives. Each has trade-offs in cost, quality, and fit.

OEM Sensors – These are manufactured to Porsche’s exact specifications. They come with the correct connector, wire length, and resistance. OEM sensors are more expensive (often $150–$250) but offer guaranteed compatibility and long service life. For owners who want to maintain originality or avoid troubleshooting, OEM is the safest choice.

Aftermarket Sensors – Many reputable brands like Bosch, Beru, and Intermotor produce sensors that match OEM specs. These are typically 30–50% cheaper. However, quality varies. Some aftermarket sensors may have slightly different connector shapes, shorter wire lengths, or resistance values that cause drivability issues. When choosing aftermarket, always verify that the part number cross-references to the exact OEM number for your model. Read the product description carefully for fitment notes.

Common Symptoms of a Failing Reference Sensor

Before replacing the sensor, confirm it is the problem. A failing reference sensor often produces these symptoms:

• Engine cranks but will not start – The most common symptom. Without a reference pulse, the ECU will not fire the ignition coils or injectors.
• Intermittent stalling – The engine may run fine then suddenly die, especially when hot.
• No spark or fuel – A diagnostic test will show no spark from the coils and no fuel pump activation.
• Check engine light – On later models with OBD I, a fault code may be stored (usually code 12 or 13 related to sensor readings).

If you suspect the sensor, test its resistance with a multimeter. The reference sensor should have a specific resistance (typically between 500 and 1000 ohms, depending on model). Compare to factory specs. Also check wiring for damage or corrosion.

Final Recommendation

Choosing the right Porsche 944 reference sensor part number comes down to accurate identification. First, confirm your car’s model year and engine. Then, either source an OEM sensor using the correct part number (944 606 117 00 for early, 944 606 119 00 for late, or 944 606 121 00 for specific variants) or select an aftermarket sensor that explicitly lists that OEM cross-reference. For most owners, sticking with OEM is the least risky option, despite the higher cost. If you choose aftermarket, buy from a reputable supplier and check the sensor visually before installation. Incorrect sensors can waste time and cause headaches. When in doubt, consult a Porsche specialist or use your VIN to verify compatibility. A properly functioning reference sensor will restore your 944’s performance and reliability.