How to replace audi key fob an audi tt key fob not working G28 Engine Speed Sensor

In this video, Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. The sensor is situated near the edges of the transmission, above the flywheel ring gear. It transmits a signal to the ECU via an uncolored wire (T55/49) and then to the tachometer located in the instrument cluster.

1. Engine Speed Sensor

Located on the edge of the transmission just above the flywheel ring gear the G28 Engine Speed Sensor sends signals to ECU pin T55/49 using an uncolored wire. The ECU then utilizes this information to regulate fuel, timig and boost. It also sends an alert to the G5 Tachometer in 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 reached TDC, and where the camshaft lies so that it can activate the spark and injectors.

If this sensor fails, the ECU will throw an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are out of sync and could indicate chain stretch or a jumped link on the upper timing chain. However the code will not be displayed on its own without additional information from other sensors (G4 and G40).

It can be a bit difficult to test since there are different pins on the connector and they all have different functions. The most effective method to test it is to measure the resistance between the ECU and the sensor. If the sensor is operational, it should be reading approximately 1000 ohms. If you're having issues with this component, look for evidence of coolant or oil in the connector bay.

2. Injectors

Yesterday accelerating full speed from highway paytoll, i experienced a big cut in power like the engine is running out of gas or injectors are not firing anymore. In the morning, i removed the spark plugs, three were soaked with gazoline and the 4th one 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 jump out but the 4th stays shut. I inspected the ground connection on ECU pins 14/55, 30/55 and 48/55. i get 0ohm. I think the issue is in another location.

I also tried to reset the PID without success. The car key replacement audi (blogfreely.net) will start if the G28 is not plugged in and is running fine when it is plugged in but it still has intermittent misfire issues at higher RPM. The coolant temperature sensor (G62) shows the wrong temp value -49c, even if I unplug it. I also noticed that the oil gauge in the cockpit shows 2 bars but the actual pressure is zero.

I don't know what to do. I think I've ruled everything else out. But i'm worried that I may have missed something. If anyone has any suggestions, please share them! TIA!

3. Fuel Pump

The fuel pump in the g28 can be activated by a signal by the RPM sensor. The GM-style transmitter is identical to the G4 sender and works on the 80,100,200, UrS, and RS2 vehicles. It is easy to find the spare in a salvage shop or parts store. It is simple to test them - simply switch your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump at the connector end facing up). They must be infinite Ohms.

4. ECU

The ECU in our 20vt turbo (3B AAN ABY ADU) engines must be aware of the speed and position of the crankshaft in order to make a decision about timing of the fuel injector, etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you are experiencing issues with either of these, the diagnostic scanner will display codes that could cause an engine shut down.

A failing G28 sensor could result in an inaccurate gearbox speed counter or a gearbox that shifts faster than normal, or a misfire in the gear. If you have any of these issues, it is likely that your sensor is failing and needs replacing. They're cheap and easy to find especially in the case of a Bosch unit like ours. You can also choose the GM version of this component is also a great option.

5. Tachometer

A failing engine sensor could cause a myriad of issues in your car. It's a vital component of your Audi's transmission, because it communicates to the ECU about how fast or slow the vehicle's crankshaft is rotating. This sensor could cause the transmission to malfunction and other components in the car to be affected.

The G5 engine sensor is located near 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 regulate the amount of fuel and boost, and also timig. It also relays it to the G5 Tachometer in instrument cluster. You can check for sensor failure by checking continuity from the sensor to the tachometer. Also, you can check continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]), and between pin T6a/1 and pin T26a/12. You should see an average resistance of 1000 ohms in these areas. This is a standard component across the audi replacement keys 80 100, 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU so good ones might be availble in wrecking yards.