The 3 Greatest Moments In Audi G28 History

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 near the edges of the transmission above the flywheel ring gear. It sends a signal to the ECU via the 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 sends a signal via the grey wire to pin T55/49. The ECU uses this information to regulate the amount of fuel and boost. It also sends an indication to the G5 Tachometer located in the instrument cluster.
The sensor is used to link the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft is TDC and where the camshaft is located so that it can trigger spark and injectors in the right way.
If this sensor fails the ECU will throw a P00160 code which means the Crank Shaft and Intake Camshaft aren't in sync, possibly indicating chain stretch or a jumped link on the upper chain of timing. However, the code won't appear on its own without additional information from other sensors (G4 and G40).
audi lost key is a bit tricky because there are two pins for the connector and they have different functions but the best method to test it is to measure resistance between the sensor and the ECU. If the sensor is operational, it should be reading around 1000 ohms. If you're experiencing issues with this component, look for signs of oil or coolant in the connector bay.
2. Injectors
Yesterday, as i was accelerating off 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. Today, i pulled out the spark plugs, three were soaked with gazoline and the 4th one was dry. When I crank the engine with no sparks, I put a piece of tissue on the top of each hole in the injector, the 3 drenched with gazoline leap out, however the 4th one stays closed. I inspected the ground connection on ECU pins 14/55, 30/55 and 48/55. i get 0ohm. I'm assuming that the issue is somewhere else.
I also tried to reset the PID but with no luck. The car will start when the G28 is disconnected and runs fine when it is plugged in but it still has the intermittent misfire issue at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature value of -49c, even if I unplug it. I also noticed that the oil gauge in the cockpit shows 2 bar while the actual pressure is 0.
I don't know what to do. I feel like i've pretty much ruled everything else out. But i'm worried that I may have missed something. If anyone has any ideas please share them! TIA!
3. Fuel Pump
The fuel pump of the g28 receives a signal from the RPM sensor. The GM-style transmitter functions similarly to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. You can easily locate a spare in a wrecking shop or a parts store. Test them out - 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 end of the connector). 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 to make a decision about timing of the fuel injector, for example. To accomplish this, it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these goes bad you will get codes on the diagnostic scanner that can cause the engine to shut down.
A failing G28 sensor could result in an inaccurate gearbox speed counter and a gearbox which shifts more quickly than normal, and/or a misfire in the gear. If you experience any of these problems, it is likely your sensor is going bad and needs replacing. They're inexpensive and easy to locate particularly in the case of an Bosch model like ours. You can also choose the GM version of this unit is also a good option.
5. Tachometer
A malfunctioning engine speed sensor could be a cause for a slew of problems in your vehicle. It's an essential component of your Audi's transmission, as it sends information to the ECU about how the car's crankshaft is spinning. If the sensor fails, it will disrupt the performance of the transmission as well as the rest of the car's components.
The G5 engine speed sensor is located at the edge of the transmission above the flywheel ring gear. It sends a signal directly to the ECU at pin T55/49 via a grey wire. The ECU uses this signal to control the flow of fuel and boost and also to timigrate. It also relays it to the G5 Tachometer in instrument cluster. You can test for sensor failure by examining the continuity of the sensor to the tachometer. Also, you can verify continuity between pin 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 approximately 1000 ohms of resistance between these two points. This is the same across the Audi 80-100-200-RS2 series, starting from the 1985 MC all the way up to the 1997 UrS AN and 1995 RS2 Du You may also find them in wrecking yards.