How to Replace an key audi G28 Engine Speed Sensor

Charles the Humble Technician shows you how to replace the G28 Engine Speed Sensor. The sensor is located on the edge of the transmission just above the flywheel ring gear. It transmits a signal to the ECU through the grey wire T55/49 and then to the tachometer on 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 signals to ECU pin T55/49 using a grey wire. The ECU then utilizes this information to regulate the boost, fuel, and timig. It also sends an indication to the G5 tachometer inside the instrument cluster.

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

If this sensor fails, the ECU will display a P00160 error message. This means that the Crank Shaft is not in alignment with the Intake Camshaft. It could also be a sign of the possibility of a chain stretch or jump in the chain link of the upper chain. However, the code won't appear on its own, without additional information from other sensors (G4 and G40).

It's a bit tricky to test as there are different pins on the connector and they all have different functions. The best method for doing this is to measure the resistance between the ECU and the sensor. It should read around 1000 ohms when it is at full operation. If you're having issues with this component, 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 massive power loss like the engine is out of gas or the injectors are not firing anymore. I took out the spark plugs this morning, three were drenched in gasoline and the fourth was dry. When i crank the engine with no sparks, I put a piece of tissue on top of each injector hole, the 3 drenched with gazoline leap out, however the 4th stay shut. I tried to test the ground connections of ECU pins 14,30, and 48/55. I found 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 if the G28 is not plugged in and it runs perfectly when it is plugged in however it is experiencing intermittent misfires at higher RPM. The temperature sensor for coolant (G62) shows the wrong temp value that is -49c even after unplugging it. Also i noticed that the oil pressure gauge in the cockpit is showing 2 bar, whereas the actual pressure is 0.0 when I crank up the engine.

I'm not sure what to do, but i feel i have pretty much ruled out everything else. I'm worried that i might have missed something. If anyone has any ideas please chime in! TIA!

3. Fuel Pump

The fuel pump of the g28 receives a signal from the RPM sensor. The GM-style transmitter is identical to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. It is easy to find a audi spare key in a wrecking shop or a parts store. It is simple to test them by putting your DMM in resistance mode and measure between pins 1 (with the bump on the connector end up) and 2 (2nd from left on the black connector's side). They should 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 decisions about timing of the fuel injectors, etc. In order to do this it utilizes a Crank Position Sensor (G4) and audi tt key (Kingranks.com) an Engine Speed Sensor (G28). If either of these go bad you will get codes on the diagnostic scanner which can lead to engine shutdown.

A failing G28 sensor could result in an inaccurate speed counter replacement key for audi a4 your gearbox, a gearbox that shifts faster than normal, or an unfire when in the gear. If you experience any of these issues it is most likely that your sensor is going bad and should be replaced. They're cheap and easy to find particularly when they're an Bosch sensor like ours. Alternatively, GM's version of this part is a good option.

5. Tachometer

A malfunctioning engine sensor can cause a myriad of issues in your vehicle. It is an important part of the transmission of your audi a3 keys because it relays information to the ECU on how fast or slowly the engine of the car is turning. This sensor can cause the transmission to malfunction and other components in the car to be affected.

The G5 engine sensor is located at the edge of transmission, above the flywheel ring. It sends a signal via a gray wire to the ECU pin T55/49. The ECU utilizes this signal to control fuel and boost, and also to timigrate. It also sends it to the G5 Tachometer located in the instrument cluster. You can check 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 as well as pin T26a/12. There should be a resistance of approximately 1000 ohms between these points. This part is common across the Audi car Key holder 80-100-200-RS2 series, starting from the 1985 MC all the way up to the 1997 UrS AN and the 1995 RS2 DU So, you may find good ones in wrecking yards.