How to Replace an audi new key G28 Engine Speed Sensor

In this video, Charles the Humble Mechanic demonstrates how to replace the G28 engine speed sensor. This sensor is situated on the outside of the transmission over the flywheel gear. It sends a signal to the ECU via the grey wire (T55/49) and then to the tachometer located 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 sends a signal via the grey wire to pin T55/49. The ECU uses this information to regulate boost and fuel. It also sends an indication to the G5 tachometer inside the instrument cluster.

The sensor is used to link the G40 Camshaft position Sensor. The ecu must know when the crankshaft is TDC and where the camshaft is located so that it can activate spark and injectors according to the situation.

If this sensor fails to function, the ECU will display an error code P00160. This indicates that the Crank Shaft is out of sync with the Intake Camshaft. It could also indicate a chain stretch or a jumped chain link in the upper timing chain. The code will not appear without the additional information provided by other sensors (G4 or G40).

It can be a bit difficult to test as there are several pins on the connector, and each one has different functions. The best way to do it is by measuring the resistance between the ECU and the sensor. It should read approximately 1000 ohms when it is in full operation. If you are having problems with this sensor, look for evidence of coolant or oil in the connector bay.

2. Injectors

Yesterday accelerating full speed from highway paytoll, i experienced massive power loss like the engine is out of gas or the injectors are not firing at all. I pulled out the spark plugs this morning, 3 were soaked in gasoline, and the fourth was unclean. When I start the engine, there are no sparks, I put a piece of tissue on the top of each of the injector holes and the 3 drenched with gazoline jump out but the 4th one stays shut. I tested the ground connection of ECU pins 14,30 and 48/55. I found 0ohm. So i assume the problem is somewhere else.

I also tried to reset the PID but with no luck. The car will start when the G28 is not plugged in and it runs perfectly when it is plugged in, but still has intermittent misfire issues at higher RPM. The coolant temperature sensor (G62) shows the wrong temperature of -49c, even if I unplug it. Also, i noticed that the oil pressure gauge in the cockpit is showing 2 bar while the actual pressure is 0.0 when i rev the engine.

I'm not certain what to do, as i think i've pretty much eliminated everything else. I'm worried that i might have missed something. If anyone has any suggestions, please share them! TIA!

3. Fuel Pump

The fuel pump in the g28 is activated by a signal by the RPM sensor. The GM-style sensor 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 at a parts store. It is simple to test them: simply put 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

Our 20vt turbo (3B AAN, ABY and ADU) engines are equipped with an ECU that needs to know the speed and position of the crankshaft in order to make a decision about fuel injector timing etc. In order to do this it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you encounter a problem with either of these, the diagnostic scanner will display codes that could cause an engine shutdown.

The signs of a failed G28 sensor are an inaccurate rev counter in the gearbox, gears shifting quicker than normal, and/or a misfire when in gear. If you are experiencing any of these issues, it is likely your sensor is going bad and should be replaced. The good news is that they are quite affordable and easily accessible, especially in the case of a Bosch model, which is what ours are. If you prefer, GM's version of this part would be a good option.

5. Tachometer

A failing engine speed sensor could be a cause for a slew of issues in your vehicle. It's an essential component of the transmission of your audi replacement keys since it sends information to the ECU on how fast or slow the engine of the car is spinning. This sensor could cause the transmission to malfunction and other components of the car key for audi replacement audi (https://scientific-Programs.science/wiki/10_Websites_To_Help_You_To_Become_A_Proficient_In_Audi_Spare_Key) to be affected.

The G5 engine speed sensor is situated on the edge of the transmission above the flywheel ring gear. It transmits a signal to the ECU at pin T55/49 through an uncolored wire. The ECU utilizes this signal to control the flow of fuel and boost and also to timigrate. It also sends it to the G5 Tachometer in instrument cluster. You can test for sensor failure by checking 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 [79trace [79]) and between pin T6a/1 and pin T26a/12. You should detect the resistance to be around 1000 ohms in these areas. This is the same across the key audi 80-100-200-RS2 series, starting beginning with the 1985 MC and up to the 1997 UrS An and 1995 RS2 Du, so you might find them in wrecking yards.