How to Replace an audi tt 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 on the edge of the transmission just above the flywheel ring gear. It transmits a signal to the ECU via a grey wire T55/49, then to the tachometer located on the instrument cluster.

1. Engine Speed Sensor

The grey wire is located on the outside of the transmission, just above the flywheel ring. The sensor transmits a signal via the grey wire to pin T55/49. The ECU then utilizes this information to regulate the boost, fuel, and timig. It also sends an indication to the G5 Tachometer located in the instrument cluster.

The sensor is used as a reference to correlate with the G40 Camshaft Position Sensor. The ecu must be aware when the crankshaft is TDC and the location of the camshaft so it can start spark and injectors according to the situation.

If this sensor fails when it fails, the ECU will display an error code P00160. This means that the Crank Shaft is out of line with the Intake Camshaft. It could also be a sign of the possibility of a chain stretch or jumpy chain link in the upper timing chain. However the code will not be displayed on its own without additional information from other sensors (G4 and G40).

Testing is a bit tricky since there are two connector pins and they perform different functions however the best method of testing it is by measuring resistance between the sensor and the ECU. It should read about 1000 ohms when it is operating at its maximum. If you're experiencing issues with this sensor, look for evidence of coolant or oil in the connector bay.

2. Injectors

Yesterday, while accelerating at full speed from the highway paytoll, i experienced an abrupt drop in power as if the engine was running out of gas or the injectors are not firing any more. I pulled out the spark plugs this morning, 3 were drenched in gasoline and the 4th was dry. When I start the engine, there are no sparks i put tissue on the top of each hole in the injector and the 3 that were drenched in gazoline leap out, however the 4th stays shut. I checked the ground connection on ECU pins 14/55, 30/55 and Audi car Key replacement 48/55. i get zero ohm. I'm assuming the issue is elsewhere.

I also tried to reset PID without success. The car can start when the G28 is unplugged and runs fine when it is connected but it still is experiencing intermittent misfires at higher RPM. The coolant sensor (G62) even if it is not plugged in, shows temperatures of -49c. Also, i noticed that the oil pressure gauge in the cockpit is showing 2 bar while the actual pressure is 0.0 if i crank up the engine.

I'm not sure what to do, but i feel i have pretty much eliminated everything else. I'm afraid i may have missed something. If anyone has suggestions, please chime in! TIA!

3. Fuel Pump

The fuel pump of the g28 receives signals from the RPM sensor. The GM-style transmitter functions similarly to the G4 sender and works on the 80,100,200, UrS, and RS2 vehicles. It is easy to find an extra in a wrecking shop or parts store. Testing them is easy by putting your DMM in resistance mode and measure between pins 1 (with the bump on the connector's end up) and 2 (2nd from left on the black connector's end). They must be infinite Ohms.

4. ECU

The ECU of our 20vt turbo (3B AAN ABY) engines requires to know both the position and speed of the crankshaft in order to make a decision about timing of fuel injectors, etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you encounter a problem with either of these sensors, the diagnostic scanner will display codes that could lead to an engine shutdown.

A malfunctioning G28 sensor could cause an inaccurate speed counter for your gearbox or a gearbox that shifts faster than normal, and/or a misfire in gear. If you experience any of these problems, it is likely your sensor is deteriorating and requires audi a3 key fob replacement. The good news is that they are very affordable and easy to find particularly if you're looking at an Bosch sensor, like ours. You can also choose the GM version of this component is also a good option.

5. Tachometer

A malfunctioning engine sensor can cause a myriad of issues within your vehicle. It is an important part of the transmission in your audi tt key replacement, as it transmits information to the ECU on how fast or slowly the engine of the car is spinning. If this sensor fails, it can cause problems for the transmission, as well as the rest of the audi car key replacement's components.

The G5 engine sensor is located near the edge of the transmission, just above the flywheel ring. It sends signals via an uncolored wire to the ECU pin T55/49. The ECU utilizes this signal to control the flow of fuel and boost and also to timigrate. It also transmits it to the G5 Tachometer located in the instrument cluster. You can test for sensor failure by checking continuity from the sensor to the tachometer. You can also check continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]) and between pin T6a/1 and pin T26a/12. You should observe approximately 1000 ohms of resistance between those two pins. This is a standard part that is found across the audi tt key fob not working 80, 100 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU, so the best ones might be availble in wrecking yards.