How to Replace an audi car key holder G28 Engine Speed Sensor

In this video Charles the humble mechanic demonstrates how to replace the G28 engine speed sensor. The sensor is located near the edges of the transmission above the flywheel ring gear. It transmits a signal to the ECU via a grey wire (T55/49) and then to the tachometer within the instrument cluster.

1. Engine Speed Sensor

The grey wire is situated on the outside of the transmission, directly above the flywheel ring. The sensor transmits signals through the grey wire to pin T55/49. The ECU then utilizes this information to regulate the flow of fuel, timig and boost. It also sends signals to the G5 Tachometer located in 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 reached TDC and also the location of the camshaft to trigger the spark and injectors.

If this sensor fails when it fails, the ECU will display a P00160 error code. This means that the Crank Shaft is not in alignment 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 timing 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 as there are several pins on the connector and they all have different functions. The best method for doing this is by measuring the resistance between the ECU and the sensor. It should read approximately 1000 ohms if the sensor is in full operation. Look for evidence of coolant or oil in the connector bay if you are experiencing issues with this part.

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 are not firing any more. I took out the spark plugs this morning, 3 were soaked with gasoline and the fourth was dry. When i crank the engine, there are no sparks, i place a tissue on top of each injector hole, the 3 drenched with gazoline leap out, however the 4th stay closed. I checked the ground connection of ECU pins 14,30, and 48/55. I got 0ohm. Therefore, i think the issue is somewhere else.

I also tried to reset the PID but with no luck. The car will start when the G28 is unplugged, and it is running fine with the G28 plugged in. However, the intermittent misfire problem still occurs at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temp value -49c even when i unplug it. Also i noticed that the oil pressure gauge in the cockpit is showing 2 bar when the actual pressure is 0.0 if i crank up the engine.

I'm not certain what to do, as i feel i have pretty much eliminated everything else. 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 can be activated by a signal by the RPM sensor. The GM-style sensor 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 wrecking yard or from a parts store. It is simple to test them - simply switch your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump at the connector end facing upwards). They should be infinite Ohms.

4. ECU

Our 20vt turbo (3B, AAN, ABY and ADU) engines are equipped with an ECU that has to know the position and speed of the crankshaft in order to make decisions regarding timing of the fuel injector, for example. It uses 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 can cause the engine to shut down.

A failing G28 sensor could result in an inaccurate gearbox speed counter and a gearbox which shifts faster than normal, or a misfire while in the gear. It is possible that the sensor is failing and requires to be replaced if you notice any of these symptoms. They're inexpensive and easy to locate, especially when they're an Bosch sensor like ours. Alternately, GM's version this component is a good option.

5. Tachometer

A faulty engine speed sensor could be the cause of numerous issues in your vehicle. It's an essential component of the Audi Tt Key Fob's transmission since it relays information to the ECU about how fast or slow the car's crankshaft is spinning. This sensor can cause the transmission to malfunction and program other components of the audi replacement car keys to be affected.

The G5 engine speed sensor is located on the edge of the transmission, above the flywheel ring gear. It sends a signal to the ECU at pin T55/49 via a grey wire. The ECU then processes this signal to control fuel, timig and boost and audi key fob (penelopetessuti.Ru) then sends it on to the G5 tachometer in the instrument cluster. You can test for sensor failure by examining the continuity of 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 [79]), and between pin T6a/1 as well as pin T26a/12. It should show approximately 1000 ohms of resistance between these two points. This is a typical component across the audi tt key fob not working 80 100 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU. Good ones might be availble in wrecking yards.