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How to Replace an Audi q7 Key G28 Engine Speed Sensor

In this video Charles the Humble Mechanic demonstrates how to replace the G28 engine speed sensor. This sensor is located at the top of the transmission, above the flywheel ring gear. It sends a message to the ECU through the grey wire T55/49 and then to the tachometer in the instrument cluster.

1. Engine Speed Sensor

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

The sensor is used as a reference to correlate with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft has reached TDC, and the location of the camshaft to trigger the spark and injectors.

If this sensor fails, the ECU will display an error code P00160. This indicates that the Crank Shaft is out of alignment with the Intake Camshaft. It could also indicate the possibility of a chain stretch or jumped chain link in the upper chain. The code will not appear without the additional information provided by other sensors (G4 or G40).

It can be a bit difficult to test because there are various connector audi a3 key fob replacement key replacement cost (https://www.Google.co.ls/) pins, and they all have different functions. The best method for doing this is to measure the resistance between the ECU and the sensor. When the sensor is fully operational, it should read about 1000 ohms. Look for signs of coolant or oil in the connector bay if there are issues with this part.

2. Injectors

Yesterday, as i was accelerating off the highway paytoll at a high speed I noticed a significant drop in power. It was like the engine had run out of gas. Or my injectors were not firing. I took out the spark plugs this morning, 3 were drenched in gasoline and the 4th was dry. I put tissue over each hole in the injector and when i start the engine with no sparks, the 3 with gazoline jump out. The 4th one remains closed. I tested the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ i get zero Ohm. I'm assuming that the issue is somewhere else.

I also tried to reset the PID with no success. The car key cover audi is able to start if the G28 is not plugged in and is running fine when it is plugged in however it is experiencing intermittent misfires at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature of -49c, even if I unplug it. Also, i noticed that the gauge for oil pressure in the cockpit is showing 2 bar while the actual pressure is 0.0 when I crank up the engine.

I'm not certain what to do, as i feel i have pretty much completely ruled out all other possibilities. I'm worried that i might have missed something. If anyone has any ideas please let me know! TIA!

3. Fuel Pump

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

4. ECU

Our 20vt turbo (3B AAN, ABY, and ADU) engines are equipped with an ECU that has to be aware of the speed and position of the crankshaft in order to make decisions about timing of the fuel injector, for example. In order to do this it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you have a problem with either one of these, the diagnostic scanner will show the codes that could trigger an engine shutdown.

A damaged G28 sensor can cause an inaccurate speed counter for your gearbox or a gearbox that shifts faster than normal, and/or a misfire in gear. It is likely that your sensor is failing and needs to be replaced if you notice any of these symptoms. The good news is they are quite affordable and easy to find particularly in the case of a Bosch model, which is what ours are. You can also choose the GM version of this unit is also a good choice.

5. Tachometer

A malfunctioning engine sensor can cause a myriad of issues in your vehicle. It's an essential component of the audi replacement key fob's transmission since it relays information to the ECU about how fast or slow the car's crankshaft is spinning. When this sensor fails, it could cause problems for the transmission and the rest of the car's components.

The G5 engine sensor is located near the edge of the transmission, just above the flywheel ring. It transmits signals via a gray wire to the ECU pin T55/49. The ECU is then able to process this signal to regulate fuel, timig and boost, and also transmitting it to the G5 tachometer inside the instrument cluster. You can test the sensor for failure by examining the continuity between it and the tachometer, between ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. You should observe around 1000 ohms of resistance between those points. This is a common feature across the audi a3 key replacement 80-100-200-RS2 range, beginning with the 1985 MC and up to the 1997 UrS An and 1995 RS2 DU You may also find some good ones in wrecking yards.