Why No One Cares About Audi G28

How to Replace an audi key fob replacement G28 Engine Speed Sensor

In this video, Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. This sensor is located on the edge of the transmission just above the flywheel ring gear. It transmits a signal to the ECU via the grey wire T55/49 and then to the tachometer on 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 then uses this information to control the boost, fuel, and timig. It also sends an alert to the G5 Tachometer within the instrument cluster.

The sensor serves 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 located so that it can trigger spark and injectors accordingly.

If this sensor fails the ECU will throw an error code P00160 which indicates that the Crank Shaft and Intake Camshaft aren't in sync and could indicate the chain is stretched or a jump link on the upper chain of timing. However, the code won't appear on its own, without additional information from other sensors (G4 and G40).

Testing is a bit tricky as there are two different pins for the connector and they serve different purposes but the best way to test it is to measure the resistance between the sensor and the ECU. It should read about 1000 ohms if the sensor is in full operation. If you're having issues with this sensor, look for evidence of coolant or oil in the connector bay.

2. Injectors

Yesterday, when accelerating from highway paytoll at a high speed I noticed a massive drop in power. It was as if the engine had run out of gas. Or, my injectors were not firing. In the morning, i removed 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 with no sparks, the 3 with gazoline jump right out. The fourth one remains shut. I tested the ground connection of ECU pins 14,30, and 48/55. I got 0ohm. I think the issue is in another location.

I also tried to reset the PID but with no luck. The car will start when the G28 is disconnected, but it works fine when the G28 plugged in. However the intermittent misfire issue still occurs at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature value of that is -49c even after unplugging it. I also noticed that the oil pressure gauge in the cockpit is showing 2 bar when the actual pressure is 0.0 if i crank up the engine.

I'm not certain what to do, but i believe that i've completely ruled out all other possibilities. I'm worried that i might have missed something. Please let me know should you have any suggestions! TIA!

3. Fuel Pump

The fuel pump on the g28 is activated by a signal sent by the RPM sensor. The GM-style transmitter is similar to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. It is easy to find an extra in a wrecking shop or a parts store. It is simple to test them - put your DMM in resistance mode and take measurements 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 uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these go wrong, you will receive codes on the diagnostic scanner which could cause engine shut down.

A failing G28 sensor could cause an inaccurate gearbox speed counter and a gearbox which shifts more quickly than normal, or a misfire in gear. It is likely that your sensor is failing and needs to be replaced if you notice any of these signs. They are cheap and easy-to-find particularly when they're a Bosch model like ours. Alternatively, the GM version of this component is also a good option.

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 keys replacement since it sends information to the ECU regarding how fast or slow the car key cover audi's engine is turning. This sensor can cause the transmission to malfunction and other car key cover audi components to be affected.

The G5 engine speed sensor is located on the outside of the transmission above the flywheel ring gear and sends a signal to the ECU at pin T55/49, via a grey wire. The ECU then uses and processes the signal to control fuel, timig and boost as well as sends it on to the G5 tachometer inside the instrument cluster. You can determine if the sensor is in failure by checking 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. You should see an average resistance of 1000 ohms between these two points. This is the same across the Audi 80-100-200-RS2 range, from the 1985 MC up to the 1997 UrS AN and the 1995 RS2 DU So, you may find good ones in wrecking yards.