How to Replace an Audi G28 Engine Speed Sensor<br /><br />Charles the Humble Technician shows you how to replace the G28 Engine Speed Sensor. The sensor is located near the edges of the transmission, above the flywheel ring gear. It sends a message to the ECU through an uncolored 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 sends a signal via the grey wire to pin T55/49. The ECU uses this information to regulate boost and fuel. It also sends an indication to the G5 Tachometer located in the instrument cluster.<br /><br />The sensor serves as a reference to correlate with the G40 Camshaft Position Sensor. The ecu must be aware when the crankshaft is TDC and where the camshaft is located so that it can activate spark and injectors accordingly.<br /><br /><br /><br />If this sensor fails, the ECU will display an error code P00160. This means that the Crank Shaft is out of alignment with the Intake Camshaft. It could also be a sign of an issue with the chain or a jumped chain link in the upper timing chain. However, <a href="https://www.g28carkeys.co.uk/audi-car-key-replacements-near-me/">lost audi key</a> won't appear on its own, without additional information from other sensors (G4 and G40).<br /><br />It is a little tricky to test since there are several connector pins, and each has its own functions. The best method for doing this is by measuring the resistance between the ECU and the sensor. When the sensor is functional, it should read about 1000 ohms. Look for signs of coolant, or oil in the connector bay if you are experiencing problems with this part.<br /><br />2. Injectors<br /><br />Yesterday, while accelerating from the highway paytoll at maximum speed I noticed a significant 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 drenched in gasoline and the fourth was unclean. When I start the engine, there are no sparks i put tissue on the top of each of the injector holes and the 3 that were drenched in gazoline pop out, but the 4th one stays shut. I inspected the ground connection on ECU pins 14/55,30/55 and 48/55 I get 0ohm. So i assume the problem is in another place.<br /><br />I also tried to reset the PID without success. The car will start when the G28 is disconnected, but it works fine when the G28 connected. However the intermittent misfire issue persists at higher RPM. The coolant sensor (G62) even when unplugged, still shows temperatures of -49c. Also i 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.<br /><br />I'm not sure what to do. I feel like i've pretty much all other possibilities out. But i am afraid 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 gets a signal from the RPM sensor. The GM-style sensor is identical to the G4 and they both work in the 80 100 200, UrS and RS2 cars which is why you can easily locate one at a junkyard or in a local parts store. It is simple to test them to do - just put your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector's side up) and 2 (2nd from left on the black end of the connector). They 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 in order to make a decision about timing of the fuel injector, for example. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you encounter a problem with either one of these, the diagnostic scanner will show codes that could cause an engine shutdown.<br /><br />Some of the symptoms of a failed G28 sensor are an inaccurate rev counter for the gearbox, gears shifting quicker than normal and/or misfiring when in gear. It is possible that your sensor is failing and requires to be replaced if you experience any of these signs. They are cheap and easy-to-find particularly if they're a Bosch model like ours. Alternatively, GM's version of this part is a good option.<br /><br />5. Tachometer<br /><br />A failing engine sensor could cause a number of problems in your vehicle. It's a crucial component of the transmission of your Audi, as it transmits information to the ECU on how fast or slow the engine is spinning. This sensor could cause the transmission to fail and other components of the car to be affected.<br /><br />The G5 engine sensor is located at the edge of the transmission, just above the flywheel ring. It transmits an electrical signal through gray wire to ECU pin T55/49. The ECU utilizes this signal to regulate the amount of fuel and boost, as well as timig. It also sends it to the G5 Tachometer inside the instrument cluster. You can test 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 to pin T6a/1 (trace [79trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. You should see approximately 1000 ohms resistance between these two points. This is a standard part across the Audi 80, 100 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU so good ones might be availble in wrecking yards.<br /><br />