toebotany4

How to Replace an Audi G28 Engine Speed Sensor Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. The sensor is situated near the edges of the transmission above the flywheel ring gear. It sends a signal to the ECU via the grey wire (T55/49) and then to the tachometer located in the instrument cluster. 1. Engine Speed Sensor The sensor is located at the edge of the transmission just above the flywheel ring gear, the G28 Engine Speed Sensor sends signals to ECU pin T55/49 via the grey wire. The ECU uses this information to control the amount of fuel and boost. It also sends an indication to the G5 tachometer in the instrument cluster. The sensor serves as a reference point to connect with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft has reached TDC and also the location of the camshaft in order to activate the spark and injectors. If this sensor fails when it fails, the ECU will display an error code P00160. This means that the Crank Shaft is out of sync with the Intake Camshaft. It could also be a sign of a chain stretch or a jump in the chain link of the upper timing chain. However, the code won't appear on its own, without additional information from other sensors (G4 and G40). It can be a bit difficult to test as there are various pins on the connector and each has its own functions. The most effective method to test it is to measure the resistance between the ECU and the sensor. When the sensor is operational, it should be reading about 1000 ohms. If you're experiencing issues with this component, look for signs of oil or coolant in the connector bay. 2. Injectors Yesterday, while accelerating at full speed from the highway paytoll, i experienced a big cut in power like the engine is running out of gas or injectors are not firing anymore. I pulled out the spark plugs this morning, 3 were soaked with gasoline and the fourth was dry. I placed a tissue over each hole in the injector and when i start the engine with no sparks, the 3 that have gazoline pop right out. The fourth one remains closed. I tested the ground connection of ECU pins 14,30, and 48/55. I found 0ohm. I assume that the problem is in another location. I also tried to reset the PID without success. The car can start when the G28 is unplugged and it runs perfectly when it is plugged in but it still is experiencing intermittent misfires at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temp value -49c even when i unplug it. I also noticed that the oil gauge in the cockpit shows 2 bar when the actual pressure is zero. I'm not certain what to do, but i feel i have pretty much ruled out everything else. I'm worried that i might have missed something. If anyone has suggestions, please share them! TIA! 3. Fuel Pump The fuel pump in the g28 gets a signal from the RPM sensor. The GM-style sender is the same as the G4 and both function in the 80 100, 200, UrS and RS2 cars so you can easily find one at a salvage yard or at a parts store. It is simple to test them – just switch your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump at the connector's end facing upwards). 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 speed and position of the crankshaft in order to make decisions regarding timing of the fuel injectors, etc. To accomplish this, it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you have a problem with either of these, the diagnostic scanner will show codes that could cause the engine shutting down. A damaged G28 sensor could result in an inaccurate speed counter for the gearbox or a gearbox that shifts faster than normal, or a misfire while in the gear. If you have any of these issues it is most likely that your sensor is going bad and needs replacing. The good news is they are very affordable and easily accessible, especially when you're looking at the Bosch model, which is what ours are. Alternately, the GM version of this component is also a great option. 5. Tachometer A failing engine speed sensor could be the cause of a slew of issues with your car. It's a vital component of the Audi's transmission since it relays information to the ECU about how the car's crankshaft is rotating. If this sensor fails, it will disrupt the performance of the transmission as well as the rest of the car's components. The G5 engine sensor is located near the edge of transmission, above the flywheel ring. It sends an electrical signal through a gray wire to the ECU pin T55/49. The ECU then uses and processes the signal to control fuel, timig, and boost and then sends it on to the G5 Tachometer located in the instrument cluster. You can test for sensor failure by examining the continuity of the sensor to the tachometer. Also, you can examine the continuity between pins T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]) and between pin T6a/1 as well as pin T26a/12. You should see around 1000 ohms of resistance between these two points. This is a typical part across the Audi 80 100, 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU. Good parts could be found in wrecking yards.