How to Replace an audi etron key G28 Engine Speed Sensor

In this video, Charles the humble mechanic demonstrates how to replace the G28 engine speed sensor. This sensor is located near the edges of the transmission, above the flywheel ring gear. It sends a signal to the ECU via a grey wire (T55/49), Audi Key Programmer then to the tachometer within the instrument cluster.

1. Engine Speed Sensor

It is located on the outside of the transmission just above the flywheel ring gear the G28 Engine Speed Sensor sends a signal to ECU pin T55/49 through a grey wire. The ECU then uses this information to control the flow of fuel, timig and boost. It also sends an alert to the G5 Tachometer in instrument cluster.

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

If this sensor fails to function, the ECU will display a P00160 error code. This indicates that the Crank Shaft is not in sync with the Intake Camshaft. It could also indicate an issue with the chain or a jump in the chain link of the upper chain of timing. However, the error code won't appear on its own, without additional information from other sensors (G4 and G40).

Testing is a bit challenging as there are two different connector pins and they have different functions but the most effective way to test it is by measuring resistance between the sensor and the ECU. It should read approximately 1000 ohms when 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, while accelerating from the highway paytoll at full speed I noticed a massive drop in power. It was like the engine was running out of gas. Or, my injectors weren't firing. This morning i pull out the spark plugs, three were drenched with gazoline the 4th one was dry. I put a piece of tissue over each injector hole and when i start the engine without sparks, the three that have gazoline pop right out. The 4th one remains shut. I checked the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I get zero Ohm. I'm assuming that the issue is in another location.

I also tried to reset the PID without success. The car will start when the G28 is disconnected, but it works fine when the G28 plugged in. However, the intermittent misfire problem continues to occur at higher RPM. The coolant temperature sensor (G62) shows the wrong temperature value of -49c even when i unplug it. I also noticed that the gauge for oil pressure in the cockpit is showing 2 bar while the actual pressure is 0.0 when I crank up the engine.

I don't know what to do. I think I've all other possibilities out. I'm afraid i may have missed something. If anyone has any suggestions, please chime in! TIA!

3. Fuel Pump

The fuel pump in the g28 can be activated by a signal sent from the RPM sensor. The GM-style sender is identical to the G4 and both function in the 80, 100, 200, UrS and RS2 cars which is why you can easily locate one at a wrecking yard or from a parts store. It is easy to test them - just put your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump at the connector end facing upwards). They must be infinite Ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY, and ADU) engines are equipped with an ECU that has to know the position and speed of the crankshaft to make decisions regarding timing of the fuel injector, for example. In order to do this it utilizes a Crank Position Sensor (G4) and audi A5 key fob [https://www.vrwant.org] an Engine Speed Sensor (G28). If you encounter a problem with either one of these, the diagnostic scanner will show codes that could cause the engine shutting down.

A malfunctioning G28 sensor could result in an inaccurate speed counter for your gearbox, a gearbox that shifts faster than normal, and/or a misfire in gear. It is likely that your sensor is failing and needs to be replaced if you experience any of these symptoms. They're inexpensive and easy to locate, especially in the case of an Bosch sensor like ours. Alternately, GM's version this part would be a good option.

5. Tachometer

A faulty engine speed sensor could be the reason behind a slew of issues in your vehicle. It's a vital component of your Audi Replacement Key Cost's transmission, since it relays information to the ECU about how the car's crankshaft is turning. If the sensor fails, it could cause problems for the transmission, as well as the other car's components.

The G5 engine speed sensor is located on the outside of the transmission, above the flywheel ring gear. It sends a signal to the ECU at pin T55/49 via an uncolored wire. The ECU then uses and processes the signal to control the flow of fuel, timig and boost, and also sends it on to the G5 Tachometer located in the instrument cluster. You can test for sensor failure by examining the continuity from the sensor to the tachometer. Additionally, you can check continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]), and between pin T6a/1 and pin T26a/12. You should observe around 1000 ohms of resistance between those points. This is the same across the audi tt key fob 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 some good ones in wrecking yards.