Where is the DME relay on a Porsche 944?

If your Porsche 944 will not start or suddenly dies on you, one of the first places you should check is the DME relay. On the older 944s, the relay is known as the fuel pump relay and is located on the fuse panel under the dash on the driver side.

How do you test a DME relay?

Using the multimeter, take a resistance reading across terminals 30 and 87. The resistance reading should be very close to zero (again between 0.1 and 0.3 ohms). If any of the readings taken above are bad, the DME relay should be replaced or if possible repaired.

What is a Porsche DME relay?

The single DME relay in your Porsche is actually two separate relays cunningly combined inside just one black-plastic housing. Then when the the starter motor is cranked, the ECU activates the second relay in the DME relay and power is supplied to the fuel pump for as long as the engine is running.

What does the ignition relay do?

The ignition relay is one of the most important electronic relays found on modern vehicles. It is usually located in the fuse and relay panel beneath the hood, and is responsible for providing power to the vehicle’s ignition system, and some of the fuel system’s components.

What does Porsche DME stand for?

Digital Motor Electronics
Digital Motor Electronics (DME) is a microprocessor based system that controls the ignition, fuel injection, oxygen sensor, and numerous ancillary functions of an automobile.

What is a DME relay on a BMW?

The DME main relay, the primary power source for nearly all engine management functions, supplies battery power to the engine ECM when the ignition is activated. A faulty DME relay can cause poor engine performance and hard starting problems. When it fails completely you may be left with an engine that doesn’t start.

Will the fuel pump run without a relay?

If the fuel pump relay fails, it will cut off power to the fuel pump, which will render it inoperable, and therefore silent when the ignition is on. While the fuel pump relay is a very simple component, it plays a very important role in the proper operation of the vehicle.

What happens if ignition relay is bad?

If the ignition relay shorts, burns out, or otherwise fails while the engine is operating it will cut off power to the fuel pump and ignition system. This will cause the vehicle to immediately stall due to fuel and spark being cut off.

How do I know if my ignition relay is bad?

Car suddenly stalls while operating: One of the most common symptoms of a failed ignition relay is a car that suddenly stalls while operating. If the ignition relay shorts, burns out, or otherwise fails while the engine is operating it will cut off power to the fuel pump and ignition system.

Is DME same as ECU?

In the automotive industry, DME is often referred to as the Engine Control Unit (ECU), under the heading of Electronic Engine Management Systems.

Where are the DME relays in a Porsche 944 Turbo?

There are two spare DME relays (red arrow) in the storage area of the panel. Check with the fuse and relay list and diagram located under the lid and remove the DME relay (red arrow). Gently wiggle and pull the relay out from its location in the panel. These DME relays fit snuggly.

When did the Porsche 944 air conditioner come out?

Year of production: 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991 Models with an air conditioner have two additional relays underneath the instrument panel next to the center console.

Is there a way to bypass the DME relay?

You can bypass the relay for testing purposes to eliminate the relay completely from your troubleshooting list. Use three pieces of 14-gauge wire along with three male spade connectors. Note: this should only be used to test or in an absolute emergency situation; do NOT regularly drive your car with this in place.