boltsnake2

How to Replace an Audi 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 the ECU via a grey wire (T55/49), then to the tachometer located in the instrument cluster. 1. Engine Speed Sensor The grey wire is situated on the outside of the transmission, directly above the flywheel ring. The sensor transmits an electrical signal through the grey wire to pin T55/49. The ECU then utilizes this information to regulate fuel, timig and boost. It also sends an indication to the G5 Tachometer located in the instrument cluster. The sensor is used to link with the G40 Camshaft position Sensor. The ecu has to know when the crankshaft has reached TDC, and where the camshaft lies so that it can activate the spark and injectors. If this sensor fails, the ECU will show a P00160 code which means the Crank Shaft and Intake Camshaft are out of sync and could indicate the chain stretching or a jump link on the upper timing chain. The code won't show without the additional information provided by other sensors (G4 or G40). It is a little tricky to test as there are various pins on the connector, and each one has different functions. The best method for doing this is to measure the resistance between the ECU and the sensor. If the sensor is operational, it should read around 1000 ohms. If you're experiencing issues with this sensor, look for signs of coolant or oil in the connector bay. 2. Injectors Yesterday, when accelerating from highway paytoll at full speed I noticed a massive decrease in power. It was as if the engine was running out of gas. Or my injectors weren't firing. I pulled out the spark plugs this morning, 3 were drenched in gasoline and the 4th was dry. I placed a tissue over each hole in the injector and when I start the engine without sparks, the three with gazoline jump out. The fourth one remains closed. I tried to test the ground connections of ECU pins 14,30 and 48/55. I found zero ohm. talks about it think the issue is somewhere else. I also tried to reset the PID but without success. The car will start when the G28 is unplugged, and it works fine when the G28 plugged in. However, the intermittent misfire problem continues to occur at higher RPM. The coolant sensor (G62), even when it is unplugged, shows a temperature of -49c. I also noticed that the oil gauge in the cockpit shows 2 bars while the actual pressure is zero. I'm not sure what to do, but i think i've pretty much completely ruled out all other possibilities. However, i'm afraid that I may have missed something. If anyone has any suggestions, 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 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 wrecking yard or from a 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 end up) and 2 (2nd from left on the black connector's side). They must be infinite Ohms. 4. ECU Our 20vt turbo (3B, AAN, ABY and ADU) engines are equipped with an ECU that has to know the position and speed of the crankshaft in order to make decisions regarding timing of the fuel injector, for example. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you encounter a problem with either of these sensors, the diagnostic scanner will show the codes that could trigger an engine shutdown. The signs of a failed G28 sensor include an inaccurate gearbox rev counter the gears are shifting faster than normal, and/or a misfire when you're in gear. If you have any of these issues it is likely that your sensor is deteriorating and requires replacement. audi q7 keys locked in car and easy to locate especially if they're an Bosch unit like ours. Alternately, GM's version this part would be a good option. 5. Tachometer A malfunctioning engine speed sensor could be the reason behind many problems in your vehicle. It's an essential component of the transmission of your Audi, as it transmits information to the ECU about how fast or slow the car's engine is spinning. This sensor could cause the transmission to malfunction and other car components to be affected. The G5 engine sensor is located at the edge of transmission, above the flywheel ring. It sends an electrical signal through gray wire to ECU pin T55/49. The ECU then processes the signal to control the flow of fuel, timig and boost, and also sends it on to the G5 Tachometer located in the instrument cluster. You can check for sensor failure by checking continuity from the sensor to the tachometer. You can also check continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]), and between pin T6a/1 and pin T26a/12. There should be an average resistance of 1000 ohms between these points. This is a typical part across the Audi 80 100, 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU. Good ones might be availble in wrecking yards.