How to Replace an Audi G28 Engine Speed Sensor<br /><br /><br /><br />Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. The sensor is situated on the edge of the transmission, above the flywheel ring gear. It sends a signal to the ECU via a grey wire (T55/49), then to the tachometer located in the instrument cluster.<br /><br />1. Engine Speed Sensor<br /><br />Located on the edge of the transmission above the flywheel ring gear the G28 Engine Speed Sensor sends a signal to ECU pin T55/49 via a grey wire. The ECU uses this information to control boost and fuel. It also sends an indication to the G5 Tachometer located in the instrument cluster.<br /><br />The sensor is used to correlate the G40 Camshaft position Sensor. The ecu must know when the crankshaft reached TDC, and the location of the camshaft in order to activate the spark and injectors.<br /><br />If this sensor fails when it fails, the ECU will display a P00160 error code. This means that the Crank Shaft is not in line with the Intake Camshaft. <a href="https://writeablog.net/jellysharon34/where-can-you-find-the-best-audi-lost-key-information">audi key replacement</a> could also be a sign of an issue with the chain or a jumped chain link in the upper chain. However, the code won't be displayed on its own without additional information from other sensors (G4 and G40).<br /><br />It is a little tricky to test because there are various connector pins, and they all have different functions. The most effective method to test it is to measure the resistance between the ECU and the sensor. It should read about 1000 ohms when the sensor is at full operation. Look for signs of coolant, or oil in the connector bay if there are issues with this part.<br /><br />2. Injectors<br /><br />Yesterday, while accelerating from the highway paytoll at a high speed, i noticed a huge drop in power. It was as if the engine was running out of gas. Or my injectors weren't firing. This morning i pull out the spark plugs. Three were drenched in gazoline, the fourth was dry. I placed a tissue over each injector hole and when i start the engine without sparks, the ones with gazoline jump right out. The 4th one stays shut. I checked the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I got zero Ohm. I'm assuming the issue is elsewhere.<br /><br />I also tried to reset the PID but without success. The car will start when the G28 is disconnected, but it runs fine with the G28 connected. However, the intermittent misfire problem continues to occur at higher RPM. The coolant sensor (G62) even if it is not plugged in, shows a temperature of -49c. I also noticed that the oil gauge in the cockpit shows 2 bar but the actual pressure is 0.<br /><br />I don't know what to do. I believe that I've all other possibilities out. But i'm worried that I may have missed something. Let me know If you have any suggestions! TIA!<br /><br />3. Fuel Pump<br /><br />The fuel pump in the g28 is activated by a signal sent by 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. You can easily find an extra in a wrecking shop or parts store. It is simple to test them 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 left on the black connector's side). <a href="https://sexton-malik.mdwrite.net/indisputable-proof-of-the-need-for-what-is-audi-comfort-key">audi key replacement</a> should be infinite ohms.<br /><br />4. ECU<br /><br />Our 20vt turbo (3B AAN, ABY, and ADU) engines are equipped with an ECU that must be aware of the speed and position of the crankshaft to make decisions about fuel injector timing etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these goes bad you will get codes on the diagnostic scanner which can lead to engine shutdown.<br /><br />Some of the symptoms of a malfunctioning G28 sensor are an inaccurate rev counter in the gearbox and gears that shift faster than normal, and/or a misfire when you're in gear. It is likely that the sensor is failing and needs to be replaced if you experience any of these signs. The good news is that they are very affordable and easily accessible particularly when you're looking at a Bosch sensor, like ours. Alternatively, the GM version of this component is also a great option.<br /><br />5. Tachometer<br /><br />A failing engine speed sensor could be a cause for many issues with your vehicle. It's a vital component of the Audi's transmission because it communicates to the ECU about how the car's crankshaft is turning. If the sensor fails, it can affect the performance of the transmission, as well as the rest of the car's components.<br /><br />The G5 engine sensor is located near the edge of the transmission, over the flywheel ring. It sends an electrical signal through gray wire to ECU pin T55/49. <a href="https://telegra.ph/10-Healthy-Audi-Battery-Key-Replacement-Habits-10-01">audi key programming near me</a> uses and processes this signal to regulate fuel, timig and boost, and also transmitting it to the G5 tachometer in the instrument cluster. You can check the sensor for failure by checking continuity between it and the tachometer. You can also check continuity between ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. You should see approximately 1000 ohms of resistance between these two points. This is a common part across the Audi 80, 100 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU, so the best ones could be available in wrecking yards.<br /><br />