How to replace audi key an audi car key G28 Engine Speed Sensor

In this video Charles the humble mechanic demonstrates how to replace the G28 engine speed sensor. This sensor is situated on the outside of the transmission just above the flywheel gear. It transmits a signal 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 located on the edge of transmission, just above the flywheel ring. This sensor sends a signal via the grey wire to pin T55/49. The ECU utilizes this information to regulate boost and fuel. It also sends an indication to the G5 tachometer inside the instrument cluster.

The sensor is used to connect with the G40 Camshaft position Sensor. The ecu must know when the crankshaft has reached TDC, and the position of the camshaft, to trigger 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 chain stretch or a jumped link on the upper timing chain. The code won't appear without the additional information provided by other sensors (G4 or 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 to measure the resistance between the sensor and the ECU. When the sensor is fully operational, it should read about 1000 ohms. Examine for evidence of coolant or oil in the connector bay if you are experiencing problems with this part.

2. Injectors

Yesterday, when accelerating from highway paytoll at full speed I noticed a massive decrease in power. It was as if the engine had run out of gas. Or my injectors were not firing. Today, i pulled out the spark plugs, 3 were drenched with gazoline the 4th one was dry. When I crank the engine, there are no sparks, i place a tissue on the top of each hole in the injector and 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 got 0ohm. So i assume the problem is elsewhere.

I also tried to reset the PID without success. The car will start when the G28 is unplugged, and it is running fine with the G28 connected. However, the intermittent misfire problem continues to occur 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 gauge in the cockpit shows 2 bar when the actual pressure is 0.

I'm not certain what to do, i believe that i've completely ruled out all other possibilities. But i am afraid i might have missed something. If anyone has any suggestions, please share them! TIA!

3. Fuel Pump

The fuel pump in the g28 receives a signal from the RPM sensor. The GM-style transmitter is the same as the G4 and they both work in the 80 100 200, UrS and RS2 cars which is why you can easily locate one at a junkyard or in a local parts store. It is easy to test them - simply 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 be aware of the position and speed the crankshaft to make decisions regarding timing of fuel injectors, etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these goes bad you will get codes on the diagnostic scanner which could cause engine shut down.

A malfunctioning G28 sensor could cause an inaccurate gearbox speed counter, a gearbox that shifts faster than normal, and/or an unfire when in the gear. If you are experiencing any of these issues it is likely that your sensor is failing and needs replacing. The good thing is that they are quite affordable and easily accessible, especially when you're looking at a Bosch unit like ours. If you prefer, GM's version of this part is an excellent choice.

5. Tachometer

A failing engine speed sensor could be the reason behind numerous issues with your car. It's a vital component of your audi Q7 replacement key's transmission, since it relays information to the ECU about how fast or slow the vehicle's crankshaft is turning. This sensor can cause the transmission to malfunction and other components of the car to be affected.

The G5 engine sensor is located at the edge of transmission, above the flywheel ring. It transmits signals via a gray 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 relays it to the G5 Tachometer in instrument cluster. You can determine if the sensor is in failure by checking continuity from the sensor to the tachometer. You can also verify continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]), and between pin T6a/1 and pin T26a/12. You should see approximately 1000 ohms resistance between those two pins. This is a standard part that is found across the audi car key replacement 80 100 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU, so the best ones might be availble in wrecking yards.