How to Replace an Audi Tt replacement Key G28 Engine Speed Sensor

In this video Charles the Humble Mechanic demonstrates how to replace the G28 engine speed sensor. The sensor is located at the top of the transmission, above the flywheel ring gear. It transmits a signal the ECU via an uncolored wire (T55/49), then to the tachometer in the instrument cluster.

1. Engine Speed Sensor

The grey wire is situated on the outside of the transmission, just above the flywheel ring. The sensor sends an electrical signal through the grey wire to pin T55/49. The ECU utilizes this information to regulate the amount of fuel and boost. It also sends an alert to the G5 Tachometer within the instrument cluster.

The sensor serves as a reference to correlate with the G40 Camshaft Position Sensor. The ecu needs to 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, the ECU will show a P00160 code which means the Crank Shaft and Intake Camshaft aren't in sync, possibly indicating the chain stretching or a jump link on the upper timing chain. The code won't show without the additional information supplied by other sensors (G4 or G40).

Testing is a bit challenging since there are two pins for the connector and they perform different functions but the most effective method to test it is to measure resistance between the sensor and Replace Audi Key; Lsrczx.Com, the ECU. It should read about 1000 ohms when the sensor is operating at its maximum. Look for signs of coolant or oil in the connector bay if there are issues with this component.

2. Injectors

Yesterday accelerating full speed from highway paytoll i had an abrupt drop in power like the engine is out of gas or the injectors aren't firing at all. I pulled out the spark plugs this morning and found that 3 were soaked in gasoline, and the fourth was dry. I put a piece of tissue over each injector hole, and when i start the engine without sparks, the ones with gazoline jump right out. The 4th one stays closed. I tested the ground connection of ECU pins 14,30 and 48/55. I found 0ohm. I'm assuming 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 intermittent misfire issues at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temp value that is -49c even after unplugging it. I also noticed that the oil pressure gauge in the cockpit shows 2 bar, whereas the actual pressure is 0.0 if i crank up the engine.

I don't know what to do. I feel like i've pretty much eliminated everything else. I'm worried that i might have missed something. If anyone has suggestions, please chime in! TIA!

3. Fuel Pump

The fuel pump of the g28 receives signals from the RPM sensor. The GM-style transmitter is similar to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. It is easy to find an extra in a wrecking shop or a parts store. It is simple to test them: simply switch your DMM into resistance mode and test the distance between pins 1 and audi A1 car key 2 (with the bump at the connector end facing upwards). They must be infinite Ohms.

4. ECU

Our 20vt turbo (3B, AAN, ABY and ADU) engines have an ECU that has to be aware of the speed and position of the crankshaft in order to make decisions regarding timing of the fuel injectors, etc. To accomplish 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 cause the engine shutting down.

A failing G28 sensor could cause an inaccurate gearbox speed counter and a gearbox which shifts more quickly than normal, or an unfire when in gear. It is likely that the sensor is failing and needs to be replaced if you notice any of these symptoms. They're cheap and easy to find particularly if they're an Bosch model like ours. Alternatively, GM's version of this part would be an option.

5. Tachometer

A faulty engine speed sensor could be the cause cost of audi key replacement numerous issues with your vehicle. It's an essential component of the transmission in your audi smart key replacement because it relays information to the ECU regarding how fast or slowly the car's engine is turning. When this sensor fails, it will disrupt the performance of the transmission, as well as the other car's components.

The G5 engine sensor is located at the edge of the transmission, just above the flywheel ring. It sends a signal via an uncolored wire to the ECU pin T55/49. The ECU utilizes this signal to regulate the flow of fuel and boost and also timig. It also transmits it to the G5 Tachometer inside the instrument cluster. You can determine if the sensor is in failure by examining the continuity of the sensor to the tachometer. Additionally, you can check continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]) and between pin T6a/1 as well as pin T26a/12. You should detect an average resistance of 1000 ohms in these areas. This part is common across the audi tt key fob 80-100-200-RS2 range, from the 1985 MC all the way up to the 1997 UrS AN and the 1995 RS2 DU You may also find good ones in wrecking yards.