How to Replace an replacement audi key G28 Engine Speed Sensor

In this video, Charles the humble mechanic demonstrates how to replace the G28 engine speed sensor. This sensor is located near the transmission's edge over the flywheel gear. It transmits a signal to the ECU via a grey wire (T55/49) which is then sent to the tachometer within the instrument cluster.

1. Engine Speed Sensor

The grey wire is situated at the edges of the transmission, just above the flywheel ring. The sensor transmits signals through the grey wire to pin T55/49. The ECU uses this information to regulate fuel and boost. It also sends signals to the G5 tachometer inside the instrument cluster.

The sensor is used as a reference point to connect with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft is TDC and where the camshaft is so it can start spark and injectors according to the situation.

If this sensor fails the ECU will display an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are out of sync and possibly indicating chain stretch or a jumped link on the upper chain of timing. However, audi A3 Key Fob replacement the error code won't appear on its own without additional information from other sensors (G4 and G40).

It is a little tricky to test since there are various connector pins, and each one has different functions. The most effective method to test it is to measure the resistance between the ECU and the sensor. It should read around 1000 ohms when the sensor is operating at its maximum. Examine for evidence of coolant or oil in the connector bay if you are experiencing issues with this part.

2. Injectors

Yesterday, while accelerating from the highway paytoll at a high speed I noticed a significant reduction in power. It was like the engine had run out of gas. Or my injectors weren't firing. This morning i pull out the spark plugs, 3 were drenched in gazoline, the fourth was dry. I placed a tissue over each injector hole, and when I start the engine without sparks, the three that have gazoline pop right out. The 4th one remains closed. I inspected the ground connection on ECU pins 14/55,30/55 and 48/55 I got zero Ohm. I'm assuming the issue is in another place.

I also tried to reset the PID but without success. The car will start when the G28 is unplugged, and it runs fine with the G28 plugged in. However, the intermittent misfire problem still occurs at higher RPM. The coolant sensor (G62) even when unplugged, still 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 don't know what to do. I believe that I've ruled everything else out. However, i'm afraid that I may have missed something. Please let me know if you have any ideas! TIA!

3. Fuel Pump

The fuel pump on the g28 is activated by a signal by the RPM sensor. The GM-style transmitter is identical to the G4 and they both work in the 80 100, 200, UrS and RS2 cars so you can easily find one at a junkyard or at a parts store. It is easy to test them - simply switch your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump at the connector end facing upwards). They must be infinite Ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY and ADU) engines are equipped with an ECU that needs to know the position and speed of the crankshaft to make a decision about timing of the fuel injectors, etc. In order to do this it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you encounter a problem with either of these, the diagnostic scanner will display the codes that could trigger an engine shutdown.

The signs of a failing G28 sensor include an inaccurate gearbox rev counter, gears shifting quicker than normal and/or misfiring when in gear. If you have any of these issues it is most likely that your sensor is deteriorating and requires replacement audi a4 key. The good news is they are very cheap and easy to find particularly when you're looking at the Bosch model, like ours. Alternatively, GM's version of this part would be an excellent choice.

5. Tachometer

A failing engine sensor could cause a myriad of issues in your car. It is an important part of the transmission in your Audi because it relays information to the ECU regarding how fast or slowly the engine of the car is turning. If this sensor fails, it will cause problems for the transmission as well as the other car's components.

The G5 engine sensor is located near the edge of the transmission, just above the flywheel ring. It sends signals via a gray wire to the ECU pin T55/49. The ECU uses this signal to control the flow of fuel and boost and also to timigrate. It also relays it to the G5 Tachometer inside the instrument cluster. You can check the sensor for any failure by checking the continuity between it and the tachometer, between 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. It should show approximately 1000 ohms resistance between these two points. This is a typical part across the audi a3 key fob replacement 80 100, 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU. Good ones could be available in wrecking yards.