How to Replace an audi car key replacement G28 Engine Speed Sensor

In this video, Charles the Humble Mechanic demonstrates how to replace the G28 engine speed sensor. This sensor is located at the edge of transmission over the flywheel gear. It transmits a signal the ECU via a grey wire (T55/49) which is then sent to the tachometer in the instrument cluster.

1. Engine Speed Sensor

The grey wire is situated on the outside of the transmission, just above the flywheel ring. This sensor sends signals through the grey wire to pin T55/49. The ECU then uses this information to control the boost, fuel, and timig. It also sends an indication to the G5 Tachometer located in the instrument cluster.

The sensor is used to connect the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft is TDC and where the camshaft is so it can activate spark and injectors in the right way.

If this sensor fails, the ECU will display a P00160 error code. This means that the Crank Shaft is out of line with the Intake Camshaft. It could also be a sign of an issue with the chain or a jumpy chain link in the upper chain. The code won't show without the additional information provided by other sensors (G4 or G40).

Testing is a bit challenging as there are two different connector pins and they have different functions but the best way to test it is to measure the resistance between the sensor and Replacement Key Audi the ECU. When the sensor is functional, it should read approximately 1000 ohms. Look for signs of coolant, or oil in the connector bay if you are experiencing issues with this component.

2. Injectors

Yesterday accelerating full speed from highway paytoll, i experienced massive power loss like the engine is out of gas or the injectors are not firing at all. In the morning, i removed the spark plugs, 3 were drenched in gazoline, Audi Key Replacement the 4th one was dry. When I crank the engine without sparks, I put a piece of tissue on the top of each of the injector holes and the 3 that were drenched in gazoline pop out, but the 4th one stays shut. I checked the ground connection of ECU pins 14,30 and 48/55. I found 0ohm. I assume that the problem is in another location.

I also tried to reset the PID with no success. The car will start when the G28 is unplugged and is running fine when it is connected however it has the intermittent misfire issue at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature value of that is -49c even after unplugging it. I also noticed that the oil gauge in the cockpit shows 2 bar but the actual pressure is zero.

I don't know what to do. I believe that I've all other possibilities out. I'm afraid i may have missed something. Please let me know If you have any suggestions! TIA!

3. Fuel Pump

The fuel pump in the g28 receives a signal from the RPM sensor. The GM-style transmitter functions similarly to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. You can easily find the spare in a salvage shop or cars parts store. It is simple to test them - put your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector end up) and 2 (2nd from the left on the black connector's end). They should be infinite Ohms.

4. ECU

The ECU of our 20vt turbo (3B AAN ABY ADU) engines must know the position and speed the crankshaft to make decisions regarding timing of fuel injectors, etc. To do this, it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these goes wrong, you will receive codes on the diagnostic scanner which can cause the engine to shut down.

Some of the signs of a malfunctioning G28 sensor are an inaccurate rev counter in the gearbox the gears are shifting faster than normal and/or a misfire when you're in gear. It is possible that your sensor is failing and requires to be replaced if you notice any of these symptoms. The good thing is that they are quite affordable and easy to find, especially in the case of a Bosch unit like ours. Alternately, the GM version of this unit is also a good option.

5. Tachometer

A malfunctioning engine sensor can cause a number of problems in your car. It's a vital component of the Audi Remote Key's transmission since it relays information to the ECU about how the car's crankshaft is turning. This sensor could cause the transmission to malfunction and other components in the car to be affected.

The G5 engine speed sensor is located on the outside of the transmission just above the flywheel ring gear. It sends a signal directly to the ECU at pin T55/49, via a grey wire. The ECU then uses and processes the signal to control fuel, timig and boost and then transmitting it to the G5 Tachometer located in the instrument cluster. You can check the sensor for failure by checking continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection on pin T6a/1 (trace [79trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. You should observe approximately 1000 ohms resistance between those two pins. This part is common across the audi lost key 80-100-200-RS2 model, ranging from the 1985 MC all the way up to the 1997 UrS An and 1995 RS2 DU, so you might find some good ones in wrecking yards.