20 Myths About Audi G28: Busted

How to Replace an audi spare key G28 Engine Speed Sensor

Charles the Humble Technician shows you how to replace the G28 Engine Speed Sensor. This sensor is situated at the edge of transmission, above the flywheel gear. It sends a message to the ECU through the grey wire T55/49 and then to the tachometer on the instrument cluster.

1. Engine Speed Sensor

The grey wire is situated on the outside of the transmission, above the flywheel ring. The sensor sends signals through the grey wire to pin T55/49. The ECU uses this information to control boost and fuel. It also sends an indicator to the G5 Tachometer located in the instrument cluster.

The sensor serves as a reference point to connect with the G40 Camshaft Position Sensor. The ecu needs to know when the crankshaft is TDC and the location of the camshaft so it can trigger 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 not in sync and could indicate chain stretch or a jumped link on the upper timing chain. However, the code won't appear on its own without additional information from other sensors (G4 and G40).

Testing can be a bit difficult because there are two connector pins and they serve different purposes but the best method to test it is to measure the resistance between the sensor and the ECU. It should read approximately 1000 ohms when it is operating at its maximum. If you're experiencing issues with this component, look for signs of coolant or oil in the connector bay.

2. Injectors

Yesterday, while accelerating from the highway paytoll at full speed, i noticed a huge 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 drenched in gazoline, the fourth 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 checked the ground connection of ECU pins 14,30, and 48/55. I got 0ohm. Therefore, i think the issue is elsewhere.

I also tried to reset the PID but without success. The car will start if the G28 is not plugged in and it runs perfectly when it is plugged in, but still is experiencing intermittent misfires at higher RPM. The coolant temperature sensor (G62) shows the wrong temp value -49c even when i unplug it. I also noticed that the oil gauge in the cockpit shows 2 bars while the actual pressure is 0.

I'm not sure what to do, as i think i've pretty much eliminated everything else. But i'm worried that I might have missed something. Please let me know If you have any suggestions! TIA!

3. Fuel Pump

The fuel pump of the g28 receives a signal from the RPM sensor. The GM-style sensor is the same as the G4 and both are used in the 80 100 200, UrS and RS2 cars which is why you can easily locate one at a salvage yard or at a parts store. It is simple to test them to do - just put your DMM in resistance mode and measure between pins 1 (with the bump on the connector end up) and 2 (2nd from the left on the black connector's side). They must be infinite Ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY, and ADU) engines have an ECU that must know the speed and position of the crankshaft in order to make decisions regarding timing of the fuel injectors, etc. To do this, it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you are experiencing issues with either one of these, the diagnostic scanner will show codes that could lead to an engine shut down.

The signs of a failed G28 sensor are an inaccurate rev counter for the gearbox, gears shifting quicker than normal and/or misfiring when you're in gear. If you experience any of these problems, it is most likely that your sensor is going bad and needs replacing. They're cheap and easy to find, especially in the case of an Bosch sensor like ours. Alternatively, GM's version of this component is an option.

5. Tachometer

A faulty engine speed sensor could be the reason behind a slew of issues in your car. It is an important part of the transmission of your programming audi key, as it transmits information to the ECU on how fast or slow the engine of the car is turning. This sensor can cause the transmission to fail and other car components to be affected.

The G5 engine speed sensor is situated on the edge of the transmission above the flywheel ring gear and sends a signal to the ECU at pin T55/49, via an uncolored wire. 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 check the sensor for failure by examining the continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. You should observe approximately 1000 ohms resistance between those points. This part is common across the audi car key replacement q7 Key (portal.Uaptc.edu) 80-100-200-RS2 model, ranging beginning with the 1985 MC and up to the 1997 UrS AN and 1995 RS2 DU So, you may find them in wrecking yards.