Its History Of Audi G28

How to Replace an Audi q3 Key G28 Engine Speed Sensor

Charles the Humble Technician shows you how to replace the G28 Engine Speed Sensor. The sensor is located near the transmission's edge over the flywheel gear. It transmits a signal to the ECU through the grey wire T55/49 and then to the tachometer 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 using an uncolored wire. The ECU uses this information to control the amount of fuel and boost. It also sends signals to the G5 tachometer in the instrument cluster.

The sensor serves as a reference to correlate with the G40 Camshaft Position Sensor. The ecu needs to know when the crankshaft reached TDC, and the location of the camshaft to trigger the spark and injectors.

If this sensor fails, the ECU will throw the P00160 error, which means the Crank Shaft and Intake Camshaft aren't in sync and could indicate the chain stretching or a jump link on the upper timing chain. The code won't show without the additional information supplied by other sensors (G4 or G40).

It is a little tricky to test since there are different pins on the connector, and they all have different functions. The best way to do it is by measuring the resistance between the ECU and the sensor. It should read about 1000 ohms when the sensor is in full operation. If you're experiencing issues with this sensor, look for signs of coolant or oil in the connector bay.

2. Injectors

Yesterday, when accelerating from highway paytoll at full speed I noticed a massive drop in power. It was as if the engine had run out of gas. Or my injectors weren't firing. I took out the spark plugs this morning, Audi key Replacement near Me (mouse click on Gtrade) 3 were soaked with gasoline and the fourth was dry. When I start the engine with no sparks, i place a tissue on the top of each of the injector holes and the 3 that were drenched in gazoline jump out but the 4th stay closed. I tested the ground connection of ECU pins 14,30 and 48/55. I got zero ohm. I think the issue is in another location.

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

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

3. Fuel Pump

The fuel pump in the g28 gets a signal from the RPM sensor. The GM-style transmitter is the same as the G4 and both are used in the 80 100, 200, UrS and RS2 cars so you can easily find one at a junkyard or from a parts store. It is simple to test them - simply put your DMM into resistance mode and test the distance between pins 1 and 2 (with the bump at the connector's end facing up). They must be infinite Ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY and ADU) engines have an ECU that needs to know the position and speed of the crankshaft to make decisions about timing of the fuel injectors, etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these goes badly, you will see codes on the diagnostic scanner which could cause engine shut down.

The signs of a failing G28 sensor are an inaccurate gearbox rev counter and gears that shift faster than normal and/or a misfire when you are in gear. If you have any of these problems, it is likely that your sensor is deteriorating and should be replaced. The good news is they are quite affordable and easy to find particularly when you're looking at the Bosch unit like ours. If you prefer, GM's version of this component is a good option.

5. Tachometer

A malfunctioning engine sensor can cause a variety of issues in your car. It's an essential component of the transmission in your audi tt key programming, as it transmits information to the ECU regarding how fast or slowly the car's engine is spinning. When this sensor fails, it can affect the performance of the transmission and the rest of the car's components.

The G5 engine sensor is located at the outskirts of transmission, above the flywheel ring. It sends an electrical signal through a gray wire to the ECU pin T55/49. The ECU is then able to process the signal to control the flow of fuel, timig and boost and then transmitting it to the G5 tachometer in 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 via pin T6a/1 (trace [79trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. It should show approximately 1000 ohms of resistance between these two points. This is a typical component across the audi key fob replacement 80 100, 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU. Good ones might be availble in wrecking yards.