The Most Pervasive Issues With Audi G28

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

Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. This sensor is situated at the edge of transmission just above the flywheel gear. It transmits a signal to the ECU through an uncolored wire T55/49, then to the tachometer located on the instrument cluster.

1. Engine Speed Sensor

The grey wire is located on the outside of the transmission, directly above the flywheel ring. The sensor transmits an electrical signal through the grey wire to pin T55/49. The ECU utilizes this information to control boost and fuel. It also sends an indication to the G5 Tachometer within the instrument cluster.

The sensor is used to connect with the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft is TDC and where the camshaft is located so that it can activate spark and injectors accordingly.

If this sensor fails when it fails, the ECU will display a P00160 error message. This indicates that the Crank Shaft is not in alignment with the Intake Camshaft. It could also be a sign of an issue with the chain or Audi advance key a jumped chain link in the upper chain. The code won't appear without the additional information supplied by other sensors (G4 or 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 to measure the resistance between the sensor and the ECU. If the sensor is functional, it should read approximately 1000 ohms. If you're experiencing issues with this part, check for signs of coolant or oil in the connector bay.

2. Injectors

Yesterday accelerating full speed from highway paytoll, I experienced an abrupt drop in power like the engine is running out of gas or injectors aren't firing anymore. I took out the spark plugs this morning and found that 3 were soaked with gasoline and the fourth was dry. When i crank the engine, there are no sparks, i place a tissue on the top of each hole in the injector and the 3 drenched with gazoline jump out but the 4th one stays shut. I tested the ground connection on ECU pins 14/55, 30/55 and 48/55. i get zero Ohm. So i assume the problem is elsewhere.

I also tried to reset PID without success. The car is able to start if the G28 is not plugged in and it runs perfectly when it is plugged in but it still has intermittent misfire issues at higher RPM. The coolant temperature sensor (G62) shows the wrong temp value -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, but i feel i have pretty much eliminated everything else. However, i'm afraid that I might have missed something. Let me know If you have any suggestions! TIA!

3. Fuel Pump

The fuel pump in the g28 can be activated by a signal from the RPM sensor. The GM-style transmitter functions similarly to the G4 sender and works on the 80,100,200, UrS, and RS2 vehicles. You can easily locate the audi spare key in a salvage shop or parts store. Testing them is easy - put your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector's side up) and 2 (2nd from the left on the black end of the connector). They must be infinite Ohms.

4. ECU

Our 20vt turbo (3B, AAN, ABY and ADU) engines have an ECU that must know the position and speed of the crankshaft to make decisions about timing of the fuel injector, for example. In order to do this it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these sensors go bad you will get codes on the diagnostic scanner that could cause engine shut down.

The signs of a malfunctioning G28 sensor include an inaccurate rev counter for the gearbox the gears are shifting faster than normal and/or a misfire when you are in gear. If you are experiencing any of these issues, it is most likely that your sensor is going bad and should be replaced. The good news is they are quite affordable and easily accessible particularly if you're looking at the Bosch unit which is what ours are. Alternately, the GM version of this part is also a good choice.

5. Tachometer

A failing engine speed sensor could be the reason behind numerous problems in your vehicle. It's a crucial component of the transmission of your programming audi key, as it transmits information to the ECU on how fast or slowly the engine is spinning. When this sensor fails, it will cause problems for the transmission, as well as the other car's components.

The G5 engine sensor is located at the edge of transmission, above the flywheel ring. It sends signals via an uncolored wire to the ECU pin T55/49. The ECU uses this signal to control fuel and boost, and also to timigrate. It also sends it to the G5 Tachometer in instrument cluster. You can check the sensor for any failure by checking the continuity between it and the tachometer. You can also check continuity between ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79]) as well as between T6a/1, and cost of audi key replacement the instrument cluster pin T26a/12. You should observe approximately 1000 ohms resistance between those two pins. This part is common across the audi new key 80-100-200-RS2 model, ranging from the 1985 MC all the way up to the 1997 UrS AN and 1995 RS2 Du, so you might find good ones in wrecking yards.