What's The Most Creative Thing That Are Happening With Audi G28

How to Replace an audi etron key G28 Engine Speed Sensor

In this video Charles the humble mechanic demonstrates how to replace audi key the G28 engine speed sensor. The sensor is located near the edges of the transmission, above the flywheel ring gear. It transmits a signal the ECU via an uncolored wire (T55/49) and then to the tachometer in the instrument cluster.

1. Engine Speed Sensor

It is located on the outside of the transmission above the flywheel ring gear, the G28 Engine Speed Sensor sends signals to ECU pin T55/49 via an uncolored wire. The ECU then uses this information to control the boost, fuel, and timig. It also sends an indication to the G5 Tachometer within the instrument cluster.

The sensor is used to correlate with the G40 Camshaft position Sensor. The ecu must be aware when the crankshaft is TDC and where the camshaft is so it can activate spark and injectors accordingly.

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

It is a little tricky to test because there are several pins on the connector, and each has its own functions. The best method for doing this is to measure the resistance between the ECU and the sensor. It should read about 1000 ohms when the sensor is at full operation. Examine for signs of coolant, or oil in the connector bay if there are issues with this part.

2. Injectors

Yesterday, when accelerating from highway paytoll at a high speed, i noticed a huge drop in power. It was as if the engine had run out of gas. Or, my injectors were not firing. I pulled out the spark plugs this morning, three were drenched in gasoline and the fourth was unclean. I put tissue over each hole in the injector and when I start the engine without sparks, the 3 with gazoline jump out. The fourth one remains shut. I tested the ground connection on ECU pins 14/55, 30/55 and 48/55. I get zero Ohm. I think the issue is elsewhere.

I also tried to reset the PID without success. The car can start if the G28 is unplugged and runs fine when it is plugged in however it has intermittent misfire issues at higher RPM. The coolant sensor (G62) even when it is unplugged, shows an ice temperature of -49c. Also, i noticed that the gauge for oil pressure in the cockpit is showing 2 bar, whereas the actual pressure is 0.0 if i crank up the engine.

I don't know what to do. I think I've eliminated everything else. I'm afraid i may have missed something. If anyone has any ideas please chime in! TIA!

3. Fuel Pump

The fuel pump in the g28 gets a signal from the RPM sensor. The GM-style transmitter is identical to the G4 sender, and both operate on the 80,100,200, Audi Replacement Key Fob UrS, and RS2 vehicles. You can easily locate 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's end up) and 2 (2nd from left on the black connector's end). 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 in order to make a decision 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 goes badly, you will see codes on the diagnostic scanner which can cause the engine to shut down.

A malfunctioning G28 sensor could result in an inaccurate speed counter for your gearbox or a gearbox that shifts more quickly than normal, or a misfire while in gear. If you experience any of these problems, it is likely that your sensor is deteriorating and needs replacing. The good news is they are very affordable and easily accessible particularly in the case of an Bosch model, which is what we have. Alternately, the GM version of this part is also a good option.

5. Tachometer

A damaged engine sensor could cause a myriad of issues in your vehicle. It's an essential component of the transmission of your audi keys since it sends information to the ECU regarding how fast or slowly the car's engine is turning. This sensor could cause the transmission to fail and other components in the car to be affected.

The G5 engine sensor is located at the edge of the transmission, just above the flywheel ring. It transmits an electrical signal through a gray wire to the ECU pin T55/49. The ECU is then able to process this signal to regulate fuel, timig, and boost and then sends it on to the G5 tachometer inside the instrument cluster. You can determine if the sensor is in failure by examining the 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 as well as pin T26a/12. You should see approximately 1000 ohms of resistance between those two pins. This is a typical part across the replacement audi key fob 80, 100, 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU. Good ones might be availble in wrecking yards.