How to Replace an audi remote key G28 Engine Speed Sensor

Charles the Humble Technician teaches how to replace the G28 Engine Speed Sensor. This sensor is situated on the outside of the transmission over the flywheel 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 located on the outside of the transmission, directly 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 a signal to the G5 Tachometer located in 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 is TDC and the location of the camshaft so it can activate spark and injectors according to the situation.

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

Testing is a bit challenging because there are two connector pins, and they serve different purposes however the best way to test it is by measuring resistance between the sensor and the ECU. When the sensor is fully operational, it should read around 1000 ohms. Look for signs of coolant, or cost of audi key replacement oil in the connector bay if you have issues with this part.

2. Injectors

Yesterday, when i was accelerating to the fullest speed from highway paytoll i had massive power loss as if the engine was running out of gas or the injectors aren't firing anymore. This morning i pull out the spark plugs. Three were drenched in gazoline, the fourth one was dry. When i crank the engine, there are no sparks i put tissue on the top of each hole in the injector and the 3 drenched with gazoline leap out, however the 4th stay closed. I tested the ground connection of ECU pins 14,30, and 48/55. I found zero ohm. So i assume the problem is somewhere else.

I also tried to reset PID but without success. The car will start when the G28 is disconnected, but it is running fine with the G28 plugged in. However the intermittent misfire issue persists at higher RPM. The coolant sensor (G62), even when unplugged, still shows an ice temperature of -49c. Also, i noticed that the gauge for oil pressure in the cockpit shows 2 bar, whereas the actual pressure is 0.0 if i crank up the engine.

I'm not sure what to do. I think I've eliminated everything else. I'm concerned that i may have missed something. If anyone has any ideas please share them! TIA!

3. Fuel Pump

The fuel pump in the g28 receives signals from 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. It is easy to find a spare in a wrecking shop or parts store. It is simple to test them - put your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector's end up) and 2 (2nd from the left on the black connector's side). They must be infinite ohms.

4. ECU

The ECU in our 20vt turbo (3B AAN ABY ADU) engines requires to be aware of the position and speed the crankshaft to make decisions regarding timing of fuel injectors, etc. In order to do this it uses a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you are experiencing issues with either of these sensors, the diagnostic scanner will show the codes that could trigger the engine shutting down.

The signs of a failed G28 sensor are an inaccurate gearbox rev counter, gears shifting quicker than normal, and/or a misfire when in gear. It is likely that your sensor is failing and requires to be replaced if you experience any of these symptoms. The good thing is that they are quite affordable and easy to find, especially when you're looking at an Bosch model, which is what we have. If you prefer, GM's version of this component is an option.

5. Tachometer

A malfunctioning engine sensor can cause a variety of issues in your car. It's a crucial component of the transmission in your audi spare key replacement since it sends information to the ECU on how fast or slow the car's engine is turning. When this sensor fails, it can cause problems for the transmission and the rest of the car's components.

The G5 engine speed sensor is situated on the edge of the transmission just above the flywheel ring gear. It sends a signal to the ECU at pin T55/49 via a grey wire. The ECU then uses and processes this signal to regulate fuel, timig, and boost and then transmitting it to the G5 Tachometer located in the instrument cluster. You can check the sensor for failure by checking continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection on pin T6a/1 (trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. There should be the resistance to be around 1000 ohms between these two points. This is a typical part that is found across the audi replacement key Cost 80 100, 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU. Good ones could be available in wrecking yards.