How to Replace an audi keyless entry G28 Engine Speed Sensor

Charles the Humble Technician teaches you how to replace the G28 Engine Speed Sensor. This sensor is located near the transmission's edge just above the flywheel gear. It transmits a signal the ECU via an uncolored wire (T55/49) which is then sent to the tachometer in the instrument cluster.

1. Engine Speed Sensor

The grey wire is located on the edge of transmission, directly above the flywheel ring. The sensor transmits signals through the grey wire to pin T55/49. The ECU uses this information to control the amount of fuel and boost. It also sends an indicator to the G5 Tachometer in instrument cluster.

The sensor is used to link with the G40 Camshaft position Sensor. The ecu must know when the crankshaft is TDC and the location of the camshaft so it can start spark and injectors accordingly.

If this sensor fails to function, the ECU will display a P00160 error message. This means that the Crank Shaft is not in sync 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 timing chain. The code won't show without the additional information provided by other sensors (G4 or G40).

It is a little tricky to test as there are several pins on the connector and each has its own functions. The most effective method to test it is to measure the resistance between the ECU and the sensor. When the sensor is fully operational, it should read approximately 1000 ohms. If you're having issues with this part, check for evidence of oil or coolant in the connector bay.

2. Injectors

Yesterday, when i was accelerating to the fullest speed from highway paytoll i had a big cut in power like the engine is out of gas or injectors are not firing anymore. I took out the spark plugs this morning, 3 were soaked in gasoline, and the fourth was unclean. I put a piece of tissue over each hole in the injector and when I start the engine with no sparks, the ones with gazoline jump out. The fourth one remains shut. I inspected the ground connection on ECU pins 14/55,30/55 and 48/55 i get zero Ohm. I assume that the problem is elsewhere.

I also tried to reset PID without success. The car will start when the G28 is disconnected, but it runs fine with the G28 connected. However, the intermittent misfire problem still occurs at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature value of -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'm not certain what to do, as i feel i have pretty much completely ruled out all other possibilities. But i'm worried that i might have missed something. If anyone has suggestions, please share them! TIA!

3. Fuel Pump

The fuel pump in the g28 can be activated by a signal sent by the RPM sensor. The GM-style transmitter functions similarly to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. You can easily find the spare in a salvage shop or 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 must be infinite Ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY and ADU) engines have an ECU that needs to be aware of the speed and position of the crankshaft to make a decision about timing of the fuel injector, for example. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you are experiencing issues with either of these sensors, the diagnostic scanner will show codes that could lead to an engine shutdown.

The signs of a failing G28 sensor include an inaccurate rev counter for the gearbox and gears that shift faster than normal and/or a misfire when you are in gear. It is likely that the sensor is failing and needs to be replaced if you notice any of these signs. The good thing is that they are very affordable and easy to find, especially in the case of an Bosch unit which is what we have. You can also choose the GM version of this unit is also a good choice.

5. Tachometer

A faulty engine speed sensor could be a cause for many problems in your car. It's an essential component of the transmission in your audi new key, as it transmits information to the ECU about how fast or slowly the car key cover audi's engine is turning. When this sensor fails, it can affect the performance of the transmission as well as the other car's components.

The G5 engine sensor is located at the outskirts 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 as well as timig. It also relays it to the G5 Tachometer located in the instrument cluster. You can determine if the sensor is in failure by examining the continuity from the sensor to the tachometer. Additionally, you can examine the continuity between pins 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. It should show approximately 1000 ohms resistance between those points. This is the same across the audi car key replacement 80-100-200-RS2 model, ranging beginning with the 1985 MC and up to the 1997 UrS AN and the 1995 RS2 DU So, you may find them in wrecking yards.