Why Nobody Cares About Audi G28

How to Replace an audi connect key G28 Engine Speed Sensor

In this video, Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. The sensor is located at the edge of transmission over the flywheel gear. It transmits a signal to the ECU via the grey wire (T55/49) which is then sent to the tachometer within 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 transmits an electrical signal through the grey wire to pin T55/49. The ECU uses this information to control boost and fuel. It also sends an indication to the G5 tachometer inside the instrument cluster.

The sensor is used to correlate with the G40 Camshaft position Sensor. The ecu must be aware of when the crankshaft has reached TDC, and where the camshaft lies so that it can activate the spark and injectors.

If this sensor fails, the ECU will display an error code P00160. This indicates that the Crank Shaft is not in sync with the Intake Camshaft. It could also be a sign of an issue with the chain or a jump in the chain link of the upper chain of timing. 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 connector pins, and they all have different functions. The most effective method to test it is by measuring the resistance between the ECU and nearest the sensor. When the sensor is fully functional, it should read approximately 1000 ohms. Examine 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 experienced an abrupt drop in power like the engine is running out of gas or the injectors aren't firing any more. Today, i pulled out the spark plugs, 3 were soaked with gazoline and the 4th one was dry. I put tissue over each hole in the injector and when I start the engine without sparks, the 3 with gazoline jump right out. The 4th one remains closed. I checked the ground connection on ECU pins 14/55, 30/55 and 48/55. I got zero Ohm. I'm assuming that the issue is somewhere else.

I also tried to reset PID without success. The car will start when the G28 is unplugged, and it is running fine with the G28 plugged in. However the intermittent misfire issue persists at higher RPM. The coolant sensor (G62) even if it is not plugged in, shows an ice temperature of -49c. 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 think I've all other possibilities out. I'm worried that i might have missed something. If anyone has suggestions, please share them! TIA!

3. Fuel Pump

The fuel pump in the g28 can be activated by a signal by the RPM sensor. The GM-style sender is the same as the G4 and both function in the 80 100, 200, UrS and RS2 cars so you can easily find one at a wrecking yard or from a parts store. Testing them is easy to do - just put your DMM in resistance mode and take measurements between pins 1 (with the bump on the connector end up) and 2 (2nd from the left on the black connector's end). They must be infinite Ohms.

4. ECU

The ECU in our 20vt turbo (3B AAN ABY) engines needs to know the speed and position of the crankshaft to make decisions regarding timing of the fuel injector, etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If either of these goes wrong, you will receive codes on the diagnostic scanner which could cause engine shut down.

A failing G28 sensor could cause an inaccurate speed counter for Key For Audi your gearbox or a gearbox that shifts faster than normal, 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 news is that they are very affordable and easily accessible particularly if you're looking at the Bosch sensor, like ours. Alternately, GM's version this component is an excellent choice.

5. Tachometer

A faulty engine speed sensor could be a cause for a slew of issues in your vehicle. It's an essential component of the audi a3 spare key's transmission since it relays information to the ECU about how fast or slow the vehicle's crankshaft is rotating. This sensor could cause the transmission to fail and other components of the car to be affected.

The G5 engine sensor is located at the outskirts of the transmission, just above the flywheel ring. It transmits signals via a gray wire to the ECU pin T55/49. The ECU utilizes this signal to control the flow of fuel and boost and also to timigrate. It also sends 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 the ECU pin T55/49 and the instrument cluster connection on pin T6a/1 (trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. You should see a resistance of approximately 1000 ohms in these areas. This is a common component across the audi car key 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.