rocketchess3

How to Replace an Audi G28 Engine Speed Sensor Charles the Humble Technician teaches how to replace the G28 Engine Speed Sensor. The sensor is situated at the top of the transmission, above the flywheel ring gear. It transmits a signal to the ECU via an uncolored wire T55/49, then to the tachometer on the instrument cluster. 1. Engine Speed Sensor The grey wire is situated on the outside of the transmission, directly above the flywheel ring. This sensor sends an electrical signal through the grey wire to pin T55/49. The ECU uses this information to control the amount of fuel and boost. It also sends an alert to the G5 Tachometer located in the instrument cluster. The sensor is used as a reference point to connect with the G40 Camshaft Position Sensor. The ecu needs to know when the crankshaft reached TDC and also where the camshaft lies to trigger the spark and injectors. If this sensor fails, the ECU will display an error code P00160. This means that the Crank Shaft is not in sync with the Intake Camshaft. It could also indicate a chain stretch or a jump in the chain link of the upper timing chain. The code won't show without the additional information provided by other sensors (G4 or G40). It can be a bit difficult to test since there are various 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 operational, it should read about 1000 ohms. If you're having issues with this part, check for signs of oil or coolant in the connector bay. 2. Injectors Yesterday, while accelerating from the highway paytoll at a high speed, i noticed a huge drop in power. It was like the engine was running out of gas. Or my injectors were not firing. In the morning, i removed the spark plugs. Three were drenched in gazoline, the 4th one was dry. I placed a tissue over each injector hole and when I turn the engine on without sparks, the ones with gazoline jump out. The fourth one remains shut. I tested the ground connection of ECU pins 14,30 and 48/55. I found 0ohm. audi replacement key service near me thekeylab.co.uk think the issue is somewhere else. I also tried to reset the PID but with no luck. The car will start if the G28 is disconnected and is running fine when it is connected, but still has intermittent misfire issues 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 bars when the actual pressure is 0. I'm not sure what to do. I think I've ruled everything else out. But i'm worried that I might have missed something. If anyone has any ideas please let me know! TIA! 3. Fuel Pump The fuel pump in the g28 is activated by a signal by the RPM sensor. The GM-style transmitter is identical to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. It is easy to find an extra in a wrecking shop or a parts store. Test them out by putting your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector's end up) and 2 (2nd from left on the black connector's side). They must be infinite ohms. 4. ECU The ECU of our 20vt turbo (3B AAN ABY ADU) engines needs to know the speed and position of the crankshaft to determine timing of fuel injectors, etc. In order to do this it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these go bad you will get codes on the diagnostic scanner which could cause engine shut down. Some of the signs of a failing G28 sensor include an inaccurate rev counter for the gearbox, gears shifting quicker than normal, and/or a misfire when you're in gear. It is possible that the sensor is failing and needs to be replaced if you experience any of these signs. They're cheap and easy to find particularly in the case of an Bosch model like ours. Alternatively, the GM version of this component is also a good option. 5. Tachometer A damaged engine sensor could cause a myriad of issues within your vehicle. It's an essential component of the transmission in your Audi, as it transmits information to the ECU regarding how fast or slowly the car's engine is turning. When this sensor fails, it will cause problems for the transmission and the rest of the car's components. The G5 engine speed sensor is located at the edge of the transmission just above the flywheel ring gear and sends a signal directly to the ECU at pin T55/49 through an uncolored wire. 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 test the sensor for any failure by checking the continuity between it and the tachometer, between ECU pin T55/49 and the instrument cluster connection to 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 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 the best ones might be availble in wrecking yards.