How to Replace an audi tt key programming q7 key (Click On this website) G28 Engine Speed Sensor

Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. The sensor is situated at the top of the transmission, above the flywheel ring gear. It transmits a signal to the ECU through the grey wire T55/49 and then to the tachometer located on the instrument cluster.

1. Engine Speed Sensor

The grey wire is situated on the outside of the transmission, above the flywheel ring. This sensor sends an electrical signal through the grey wire to pin T55/49. The ECU then utilizes this information to regulate fuel, timig 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 has to be aware of when the crankshaft has reached TDC and also the position of the camshaft, in order to activate the spark and injectors.

If this sensor 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 jumpy chain link in the upper timing chain. However, the code won't be displayed on its own without additional information from other sensors (G4 and G40).

Testing is a bit tricky since there are two pins for the connector and they perform different functions but the best method of testing it is by measuring resistance between the sensor and the ECU. If the sensor is functional, it should read around 1000 ohms. If you are having problems with this part, check for signs of oil or coolant in the connector bay.

2. Injectors

Yesterday accelerating full speed from highway paytoll, I experienced massive power loss as if the engine was running out of gas or the injectors are not firing anymore. I pulled out the spark plugs this morning and found that 3 were drenched in gasoline and the 4th was dry. When i crank the engine with no sparks i put tissue on top of each injector hole, the 3 drenched with gazoline leap out, however the 4th stay shut. I checked the ground connection of ECU pins 14,30, and 48/55. I found 0ohm. Therefore, i think the issue is somewhere else.

I also tried to reset the PID with no success. The car is able to start when the G28 is unplugged 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 when i unplug it. Also i noticed that the gauge for oil pressure in the cockpit shows 2 bar when 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 all other possibilities out. But i am afraid i might have missed something. If anyone has any ideas please chime in! TIA!

3. Fuel Pump

The fuel pump of the g28 receives signals from the RPM sensor. The GM-style transmitter is identical to the G4 sender, and both operate 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 - 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 up). They should be infinite ohms.

4. ECU

The ECU of our 20vt turbo (3B AAN ABY ADU) engines needs to know both the position and speed of the crankshaft to make decisions regarding timing of the fuel injector, etc. In order to do this it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these go badly, you will see codes on the diagnostic scanner that could cause engine shut down.

A failing G28 sensor can cause an inaccurate speed counter for the gearbox, a gearbox that shifts more quickly than normal, and/or an unfire when in gear. It is possible that the sensor is failing and needs to be replaced if you encounter any of these symptoms. The good news is that they are very cheap and easily accessible, especially when you're looking at an Bosch model, which is what we have. Alternately, GM's version this part is a good option.

5. Tachometer

A failing engine sensor could cause a myriad of issues in your vehicle. It's a crucial component of the transmission of your audi key fob not working since it sends information to the ECU regarding how fast or slowly the engine is turning. This sensor could cause the transmission to malfunction and other components in the replacement car key audi to be affected.

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 fuel and boost, and also to timigrate. It also sends it to the G5 Tachometer in instrument cluster. You can check for sensor failure by checking continuity from the sensor to the tachometer. You can also 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 and pin T26a/12. There should be an average resistance of 1000 ohms between these points. This is a standard part across the audi a1 key replacement 80, 100, 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU so good ones might be availble in wrecking yards.