Incontestable Evidence That You Need Audi G28

How to Replace an audi a3 spare key G28 Engine Speed Sensor

In this video Charles the humble mechanic demonstrates how to replace audi key the G28 engine speed sensor. This sensor is located near the transmission's edge over the flywheel gear. It transmits 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 located at the edges of the transmission, above the flywheel ring. This sensor sends a signal via the grey wire to pin T55/49. The ECU then uses this information to control fuel, timig and boost. It also sends a signal to the G5 tachometer in the instrument cluster.

The sensor is used to correlate 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 start spark and injectors according to the situation.

If this sensor fails the ECU will throw 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 chain of timing. However the code will not appear on its own, without additional information from other sensors (G4 and G40).

Testing is a bit tricky as there are two different pins for the connector and they perform different functions however the best method of testing it is by measuring resistance between the sensor and the ECU. When the sensor is fully operational, it should read around 1000 ohms. If you're having 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 massive decrease in power. It was as if the engine was running out of gas. Or, my injectors weren't firing. I took out the spark plugs this morning, three were soaked with gasoline and the fourth was dry. When I start the engine without sparks, I put a piece of tissue on the top of each of the injector holes and the 3 drenched with gazoline pop out, but the 4th one stays closed. I checked the ground connection on ECU pins 14/55, 30/55 and 48/55. I get zero ohm. I assume that the problem is somewhere else.

I also tried to reset PID without success. The car will start when the G28 is disconnected, but it runs fine with the G28 connected. However, the intermittent misfire problem continues to occur at higher RPM. The coolant temperature sensor (G62) shows the wrong temperature of -49c, even if I unplug it. I also noticed that the oil gauge in the cockpit shows 2 bar when the actual pressure is 0.

I'm not sure what to do, as i think i've pretty much ruled out everything else. However, i'm afraid that I may have missed something. If anyone has any ideas please share them! TIA!

3. Fuel Pump

The fuel pump on the g28 is activated by a signal by the RPM sensor. The GM-style transmitter is identical to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. You can easily locate a spare in a wrecking shop or parts store. It is simple to test them: simply put your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump on the connector's edge facing up). They must be infinite Ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY, and ADU) engines are equipped with an ECU that needs to know the position and speed of the crankshaft in order to make a decision about timing of the fuel injector, for example. In order to do this it uses a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you encounter a problem with either of these, the diagnostic scanner will display the codes that could trigger the engine shutting down.

Some of the symptoms of a malfunctioning G28 sensor include an inaccurate rev counter in the gearbox and gears that shift faster than normal and/or misfiring when you are in gear. It is likely that the sensor is failing and requires to be replaced if you encounter any of these symptoms. They're inexpensive and easy to locate particularly in the case of an Bosch model like ours. Alternately, GM's version this part is a good option.

5. Tachometer

A failing engine speed sensor could be the cause of many problems in your vehicle. It is a crucial part of your audi remote Key's transmission, because it communicates to the ECU about how fast or slow the car's crankshaft is rotating. If the sensor fails, it will cause problems for the transmission and the other car's components.

The G5 engine speed sensor is situated on the edge of the transmission just above the flywheel ring gear. It transmits a signal to the ECU at pin T55/49, via an uncolored wire. The ECU uses this signal to control fuel and boost, Audi Q7 Key as well as timig. It also transmits it to the G5 Tachometer in instrument cluster. You can determine if the sensor is in failure by examining the continuity of the sensor to the tachometer. Also, you can check continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]), and between pin T6a/1 and pin T26a/12. You should see approximately 1000 ohms of resistance between these two points. This is a typical part across the audi a4 key replacement 80, 100, 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU, so the best ones might be availble in wrecking yards.