How to Replace an Audi G28 Engine Speed Sensor<br /><br />Charles the Humble Technician teaches you how to replace the G28 Engine Speed Sensor. This sensor is situated at the edge of transmission, above the flywheel gear. It sends a message to the ECU via a grey wire T55/49, then to the tachometer located on the instrument cluster.<br /><br />1. Engine Speed Sensor<br /><br />The grey wire is located on the outside of the transmission, just above the flywheel ring. The sensor transmits a signal via the grey wire to pin T55/49. <a href="https://posteezy.com/productive-rant-about-audi-key-replacement">audi replacement key uk</a> uses this information to control fuel, timig and boost. It also sends an alert to the G5 Tachometer located in the instrument cluster.<br /><br />The sensor is used to connect the G40 Camshaft position Sensor. The ecu must know when the crankshaft has reached TDC and also where the camshaft lies in order to activate the spark and injectors.<br /><br />If this sensor fails the ECU will display a P00160 code which means the Crank Shaft and Intake Camshaft are out of sync and could indicate chain stretch or a jumped link on the upper chain of timing. However the code will not appear on its own without additional information from other sensors (G4 and G40).<br /><br />Testing is a bit tricky as there are two different connector pins, and they serve different purposes but the most effective way to test it is to measure the resistance between the sensor and the ECU. It should read approximately 1000 ohms if the sensor is operating at its maximum. Look for evidence of coolant or oil in the connector bay if you are experiencing issues with this component.<br /><br /><br /><br />2. Injectors<br /><br />Yesterday accelerating full speed from highway paytoll, i experienced an abrupt drop in power like the engine is running out of gas or the injectors are not firing at all. This morning i pull out the spark plugs, 3 were drenched in gazoline, the fourth one was dry. When i crank the engine, there are no sparks, i place a tissue on top of each injector hole and the 3 that were drenched in gazoline pop out, but the 4th stays closed. I tried to test the ground connections of ECU pins 14,30, and 48/55. I got zero ohm. I think the issue is elsewhere.<br /><br />I also tried to reset the PID without success. The car will start when the G28 is unplugged, and it is running fine with the G28 connected. However, the intermittent misfire problem still occurs at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature value of -49c, even if I unplug it. I also noticed that the oil gauge in the cockpit shows 2 bar while the actual pressure is zero.<br /><br />I'm not sure what to do. I feel like i've pretty much eliminated everything else. I'm worried that i might have missed something. Please let me know If you have any suggestions! TIA!<br /><br />3. Fuel Pump<br /><br />The fuel pump in the g28 receives signals from the RPM sensor. The GM-style transmitter is similar to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. It is easy to find the spare in a salvage shop or parts store. Test them out to do - just put 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 connector's side). They must be infinite Ohms.<br /><br />4. ECU<br /><br />Our 20vt turbo (3B AAN, ABY, and ADU) engines have an ECU that needs to know the speed and position of the crankshaft to make decisions about fuel injector timing etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If you have a problem with either one of these, the diagnostic scanner will show codes that could lead to an engine shut down.<br /><br />A failing G28 sensor can cause an inaccurate speed counter for the gearbox or a gearbox that shifts more quickly than normal, or a misfire while in gear. It is probable that your sensor is failing and needs to be replaced if you experience any of these symptoms. They're inexpensive and easy to locate, especially when they're a Bosch unit like ours. Alternatively, the GM version of this unit is also a great option.<br /><br />5. Tachometer<br /><br />A faulty engine speed sensor could be the cause of many problems in your vehicle. It's a vital component of the Audi's transmission because it communicates to the ECU about how fast or slow the vehicle's crankshaft is rotating. This sensor could cause the transmission to fail and other car components to be affected.<br /><br />The G5 engine sensor is located at the edge of transmission, above the flywheel ring. It transmits signals via an uncolored wire to the ECU pin T55/49. The ECU then processes this signal to control the flow of fuel, timig and boost and then sends it on to the G5 tachometer inside the instrument cluster. You can test for sensor failure by examining the continuity of the sensor to the tachometer. Additionally, you can verify continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]) and between pin T6a/1 as well as pin T26a/12. You should detect an average resistance of 1000 ohms between these two points. This is the same across the Audi 80-100-200-RS2 series, starting from the 1985 MC up to the 1997 UrS AN and 1995 RS2 DU You may also find good ones in wrecking yards.<br /><br />