10 Quick Tips About Audi G28

How to Replace an audi a4 replacement key G28 Engine Speed Sensor

Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. The sensor is located on the outside of the transmission, above the flywheel gear. It sends a signal to the ECU via an uncolored wire (T55/49), then to the tachometer located in the instrument cluster.

1. Engine Speed Sensor

The grey wire is situated at the edges of the transmission, above the flywheel ring. The sensor transmits an electrical signal through the grey wire to pin T55/49. The ECU then uses this information to control fuel, timig and boost. It also sends an alert to the G5 Tachometer within the instrument cluster.

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

If this sensor fails to function, the ECU will display a P00160 error code. This indicates that the Crank Shaft is not in 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 won't appear without the additional information provided by other sensors (G4 or G40).

It's a bit tricky to test because there are various pins on the connector, and each one has different functions. The best way to do it is by measuring the resistance between the ECU and the sensor. It should read approximately 1000 ohms when it is operating at its maximum. If you're experiencing issues with this component, look for evidence of coolant or oil in the connector bay.

2. Injectors

Yesterday, while accelerating at full speed from the highway paytoll, I experienced a big cut in power like the engine is running out of gas or injectors are not firing at all. Today, i pulled out the spark plugs, three were drenched with gazoline the fourth was dry. I placed a tissue over each injector hole, and when i turn the engine on without sparks, the 3 with gazoline jump right out. The 4th one remains shut. I tried to test the ground connections of ECU pins 14,30 and 48/55. I got zero ohm. So i assume the problem is in another place.

I also tried to reset the PID with no success. The car will start when the G28 is disconnected, but it works fine when the G28 plugged in. However, the intermittent misfire problem continues to occur at higher RPM. The coolant sensor (G62), even when it is unplugged, shows a temperature of -49c. Also, i noticed that the gauge for oil pressure in the cockpit is showing 2 bar while the actual pressure is 0.0 if i crank up the engine.

I don't know what to do. I think I've all other possibilities out. I'm afraid i may 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 functions similarly to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. You can easily find a audi spare key replacement in a wrecking shop or a parts store. It is easy to test them - simply put your DMM into resistance mode and measure the distance between pins 1 and audi replacement key service near me 2 (with the bump on the connector's edge facing upwards). They should be infinite ohms.

4. ECU

The ECU of our 20vt turbo (3B AAN ABY) engines must know the position and speed of the crankshaft in order to make a decision about 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 sensors go badly, you will see codes on the diagnostic scanner that can lead to engine shutdown.

A failing G28 sensor could result in an inaccurate gearbox speed counter, a gearbox that shifts faster than normal, or an unfire when in the gear. It is likely that the sensor is failing and needs to be replaced if you notice any of these symptoms. The good thing is that they are quite affordable and readily available, especially when you're looking at a Bosch unit like ours. If you prefer, GM's version of this part would be an excellent choice.

5. Tachometer

A damaged engine sensor could cause a variety of issues within your vehicle. It is an important part of the transmission in your audi a1 key fob because it relays information to the ECU about how fast or nearest slow the engine 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 the transmission, just above the flywheel ring. It sends an electrical signal through gray wire to ECU pin T55/49. The ECU then uses and processes the signal to control fuel, timig and boost and then transmitting it to the G5 tachometer in the instrument cluster. You can determine if the sensor is in failure by checking continuity from the sensor to the tachometer. Also, you can verify continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]) and between pin T6a/1 as well as pin T26a/12. There should be a resistance of approximately 1000 ohms in these areas. This is a standard part across the Audi Key Blade 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.