Why Nobody Cares About Audi G28 How to Replace an Audi G28 Engine Speed Sensor

In this video Charles the humble mechanic demonstrates how to replace the G28 engine speed sensor. The sensor is situated at the top of the transmission just above the flywheel ring gear. It sends a signal to the ECU via the grey wire (T55/49) and then to the tachometer located in the instrument cluster.

1. Engine Speed Sensor

It is located on the outside of the transmission above the flywheel ring gear the G28 Engine Speed Sensor sends an electrical signal to ECU pin T55/49 through an uncolored wire. The ECU then uses this information to control fuel, timig and boost. It also sends signals to the G5 tachometer inside the instrument cluster.

The sensor is used to link the G40 Camshaft position Sensor. The ecu must know when the crankshaft is TDC and the location of the camshaft so it can start spark and injectors in the right way.

If this sensor fails the ECU will display the P00160 error, which means the Crank Shaft and Intake Camshaft are not in sync and could indicate chain stretch or a jumped link on the upper chain of timing. The code won't show without the additional information provided by other sensors (G4 or G40).

Testing can be a bit difficult as there are two different pins for the connector and they perform different functions but the best method to test it is by measuring resistance between the sensor and the ECU. When the sensor is operational, it should read about 1000 ohms. Examine for signs of coolant or oil in the connector bay if there are issues with this part.

2. Injectors

Yesterday, while accelerating from the highway paytoll at maximum speed I noticed a massive drop in power. It was like the engine was running out of gas. Or, my injectors were not firing. In the morning, i removed the spark plugs. Three were soaked with gazoline and the fourth one was dry. When I crank the engine without sparks, I put a piece of tissue on the top of each hole in the injector and the 3 drenched with gazoline jump out but the 4th one stays closed. I tested the ground connection of ECU pins 14,30, and 48/55. I got zero ohm. So i assume the problem is elsewhere.

I also tried to reset PID but without success. The car can start if the G28 is disconnected and is running fine when it is connected but it still is experiencing intermittent misfires at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature value of -49c even when i unplug it. I also noticed that the gauge for oil pressure in the cockpit is showing 2 bar, whereas the actual pressure is 0.0 if i crank up the engine.

I don't know what to do. I feel like i've pretty much ruled everything else out. I'm afraid i may have missed something. If anyone has any ideas please share them! TIA!

3. Fuel Pump

The fuel pump in the g28 receives signals from the RPM sensor. The GM-style transmitter functions similarly to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. It is easy to find a spare in a wrecking shop or a parts store. It is easy to test them: simply switch your DMM into resistance mode and test the distance between pins 1 and 2 (with the bump at the connector's end facing upwards). They should be infinite Ohms.


4. audi car key of our 20vt turbo (3B AAN ABY) engines must know the position and speed the crankshaft to make decisions regarding fuel injector timing, etc. To do this, it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you have a problem with either of these, the diagnostic scanner will display codes that could lead to an engine shut down.

Some of the symptoms of a failing G28 sensor include an inaccurate gearbox rev counter and gears that shift faster than normal and/or a misfire when in gear. If you experience any of these issues, it is likely that your sensor is failing and requires replacement. genuine audi key replacement and easy to locate, especially if they're a Bosch unit like ours. Alternately, the GM version of this part is also a good choice.

5. Tachometer

A failing engine sensor could cause a variety of issues within your vehicle. It's an essential component of the transmission in your Audi since it sends information to the ECU about how fast or slow the engine is spinning. If this sensor fails, it will disrupt the performance of the transmission as well as the rest of the car's components.

The G5 engine speed sensor is located on the outside of the transmission just above the flywheel ring gear. It transmits a signal to the ECU at pin T55/49 through a grey wire. The ECU then uses and processes this signal to control fuel, timig and boost and then transmitting it to the G5 tachometer inside the instrument cluster. You can check the sensor for failure by examining the continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. You should see approximately 1000 ohms resistance between those two pins. This is a common component across the Audi 80 100 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU so good parts could be found in wrecking yards.