10 Quick Tips About Audi G28

How to Replace an audi spare keys G28 Engine Speed Sensor

Charles the Humble Technician teaches you how to replace the G28 Engine Speed Sensor. This sensor is situated on the outside of the transmission just above the flywheel gear. It transmits a signal to the ECU via a grey wire T55/49, then to the tachometer in the instrument cluster.

1. Engine Speed Sensor

The sensor is located at the edge of the transmission, above the flywheel ring gear G28 Engine Speed Sensor sends a signal to ECU pin T55/49 using the grey wire. The ECU then utilizes this information to regulate fuel, timig and boost. It also sends an indication to the G5 Tachometer located in the instrument cluster.

The sensor serves as a reference for comparing with the G40 Camshaft Position Sensor. The ecu needs to know when the crankshaft reached TDC, and the position of the camshaft, in order to activate the spark and injectors.

If this sensor fails, the ECU will display a P00160 error code. This means that the Crank Shaft is not in alignment with the Intake Camshaft. It could also be a sign of the possibility of a chain stretch or jumpy chain link in the upper timing chain. The code will not appear without the additional information supplied by other sensors (G4 or G40).

It can be a bit difficult to test since there are various pins on the connector, and they all have different functions. The most effective method to test it is by measuring the resistance between the ECU and the sensor. It should read about 1000 ohms if the sensor is in full operation. If you're having issues with this component, look for evidence of oil or coolant in the connector bay.

2. Injectors

Yesterday, when accelerating from highway paytoll at maximum speed I noticed a massive drop in power. It was as if the engine had run out of gas. Or, my injectors weren't firing. I took out the spark plugs this morning, three were soaked with gasoline and the 4th was dry. When I crank the engine without sparks i put tissue on the top of each of the injector holes and the 3 that were drenched in gazoline jump out but the 4th stay closed. I inspected the ground connection on ECU pins 14/55,30/55 and 48/55 I got 0ohm. Therefore, i think the issue is in another place.

I also tried to reset the PID without success. The car will start when the G28 is unplugged and it runs perfectly when it is connected, but still has intermittent misfire issues at higher RPM. The coolant sensor (G62), even when unplugged, still shows an ice temperature of -49c. I also noticed that the oil gauge in the cockpit shows 2 bars but the actual pressure is zero.

I'm not sure what to do. I believe that I've all other possibilities out. I'm concerned that i may have missed something. If anyone has any suggestions, please let me know! TIA!

3. Fuel Pump

The fuel pump on the g28 is activated by a signal sent from the RPM sensor. The GM-style sensor is identical to the G4 and both are used in the 80, 100 200, UrS and RS2 cars so you can easily find one at a salvage yard or in a local parts store. Test them out by putting your DMM in resistance mode and take measurements 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 should be infinite Ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY and ADU) engines are equipped with an ECU that must know the speed and position of the crankshaft in order to make decisions regarding timing of the fuel injector, for example. To accomplish this, it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these go wrong, you will receive codes on the diagnostic scanner that can cause the engine to shut down.

Some of the symptoms of a malfunctioning G28 sensor are an inaccurate gearbox rev counter and gears that shift faster than normal and/or a misfire when you're in gear. If you have any of these issues it is most likely that your sensor is failing and should be replaced. The good news is that they are quite affordable and readily available, especially when you're looking at a Bosch unit like ours. If you prefer, GM's version of this component is an excellent choice.

5. Tachometer

A malfunctioning engine speed sensor could be a cause for numerous problems in your car. It's an essential component of the transmission in your audi tt replacement key because it relays information to the ECU on how fast or slowly the car's engine is turning. If this sensor fails, it can 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 and sends a signal to the ECU at pin T55/49 through a grey wire. The ECU is then able to process this signal to control fuel, timig, and boost, and also sends it on to the G5 tachometer in the instrument cluster. You can determine if the sensor is in failure by examining the continuity from the sensor to the tachometer. You can also verify continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]) and between pin T6a/1 as well as pin T26a/12. You should see an average resistance of 1000 ohms between these two points. This is a standard part across the audi tt key fob not working 80, 100 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU so good ones could be available in wrecking yards.