How to Replace an audi key fob not working G28 Engine Speed Sensor

In this video, Charles the Humble Mechanic demonstrates how to replace the G28 engine speed sensor. The sensor is situated on the edge of the transmission, above the flywheel ring gear. It transmits a signal to the ECU via a grey wire T55/49, then to the tachometer on 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 a grey wire. The ECU utilizes this information to regulate fuel and boost. It also sends an indicator to the G5 Tachometer within the instrument cluster.

The sensor is used to correlate with the G40 Camshaft position Sensor. The ecu has to be aware of when the crankshaft has reached TDC, and the location of the camshaft so that it can activate the spark and injectors.

If this sensor fails the ECU will throw an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are out of sync and possibly indicating the chain stretching or a jump link on the upper chain of timing. The code won't show without the additional information provided by other sensors (G4 or G40).

It can be a bit difficult to test because there are different connector pins, and they all have different functions. The best way to do it is to measure the resistance between the ECU and the sensor. It should read about 1000 ohms when it is operating at its maximum. Check for signs of coolant or oil in the connector bay if you have issues with this part.

2. Injectors

Yesterday, when accelerating from highway paytoll at full speed I noticed a significant 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 and found that 3 were soaked with gasoline and the fourth was unclean. I put tissue over each injector hole, and when i start the engine without sparks, the ones that have gazoline pop right out. The 4th one stays closed. I tested the ground connection on ECU pins 14/55,30/55 and 48/55 I get zero Ohm. I assume that the problem is somewhere else.

I also tried to reset PID but without success. The car will start when the G28 is unplugged, and Audi Advanced Key it is running fine with the G28 plugged in. However the intermittent misfire issue persists at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature value of that is -49c even after unplugging it. I also noticed that the gauge for oil pressure in the cockpit is showing 2 bar when the actual pressure is 0.0 if i crank up the engine.

I'm not sure what to do, as i believe that i've ruled out everything else. I'm concerned that i may have missed something. Let audi key replacement near 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 is identical to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. You can easily locate the spare in a salvage shop or a parts store. It is simple to test them - simply switch your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump at the connector's end facing upwards). They must be infinite Ohms.

4. ECU

The ECU of our 20vt turbo (3B AAN ABY ADU) engines requires to be aware of the speed and position of the crankshaft to make decisions regarding fuel injector timing, Audi A4 Key Replacement etc. To do this, it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you have a problem with either of these, the diagnostic scanner will display codes that could cause an engine shut down.

A damaged G28 sensor can cause an inaccurate speed counter for your gearbox or a gearbox that shifts more quickly than normal, or a misfire in gear. If you are experiencing any of these problems, it is most likely that your sensor is going bad and should be replaced. The good news is they are very cheap and readily available particularly when you're looking at a Bosch sensor, which is what ours are. You can also choose the GM version of this unit is also a great option.

5. Tachometer

A malfunctioning engine speed sensor could be the reason behind numerous issues in your vehicle. It's an essential component of the transmission in your replacement audi a3 key, as it transmits information to the ECU on how fast or slowly the engine of the car is spinning. If the sensor fails, it can cause problems for the transmission and the rest of the car's components.

The G5 engine speed sensor is located at the outside of the transmission just above the flywheel ring gear. It sends a signal directly to the ECU at pin T55/49, via a grey wire. The ECU utilizes this signal to regulate the flow of fuel and boost and also timig. It also sends it to the G5 Tachometer inside the instrument cluster. You can determine if the sensor is in failure by checking continuity from the sensor to the tachometer. Also, you can 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 detect the resistance to be around 1000 ohms between these points. This is the same across the audi smart key replacement 80-100-200-RS2 range, beginning with the 1985 MC and up to the 1997 UrS AN and the 1995 RS2 DU So, you may find them in wrecking yards.