How to Replace an audi a3 key fob replacement G28 Engine Speed Sensor

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

1. Engine Speed Sensor

It is located on the outside of the transmission just above the flywheel ring gear G28 Engine Speed Sensor sends a signal to ECU pin T55/49 using an uncolored wire. The ECU uses this information to regulate boost and fuel. It also sends signals to the G5 tachometer inside the instrument cluster.

The sensor is used as a reference point to connect with the G40 Camshaft Position Sensor. The ecu needs to know when the crankshaft is TDC and the location of the camshaft so it can activate spark and injectors accordingly.

If this sensor fails the ECU will throw the P00160 error, 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 supplied by other sensors (G4 or G40).

It’s a bit tricky to test as there are different pins on the connector, and each one has different functions. The best way to do it is to measure the resistance between the ECU and the sensor. It should read around 1000 ohms if the sensor is operating at its maximum. Examine for evidence of coolant or oil in the connector bay if you have problems with this part.

2. Injectors

Yesterday, when i was accelerating to the fullest speed from highway paytoll i had massive power loss like the engine is out of gas or the injectors aren’t firing at all. I took out the spark plugs this morning and found that 3 were soaked with gasoline and the fourth was dry. I placed a tissue over each hole in the injector and when I turn the engine on without sparks, the three that have gazoline pop right out. The 4th one remains shut. I checked the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ i get zero ohm. I assume that the problem is elsewhere.

I also tried to reset the PID without success. The car will start when the G28 is disconnected, Audi Key Replacement Cost Uk but it is running fine with the G28 plugged in. However, the intermittent misfire problem persists at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature of that is -49c even after unplugging it. I also noticed that the oil gauge in the cockpit shows 2 bar but the actual pressure is zero.

I’m not sure what to do. I feel like i’ve pretty much eliminated everything else. I’m worried that i might have missed something. If anyone has any suggestions, please chime in! TIA!

3. Fuel Pump

The fuel pump in the g28 can be activated by a signal sent by the RPM sensor. The GM-style transmitter is identical to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. You can easily locate the spare in a salvage shop or parts store. It is simple to test them to do – just put your DMM in resistance mode and measure 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

Our 20vt turbo (3B AAN, ABY, and ADU) engines have an ECU that must know the position and speed of the crankshaft to make a decision about timing of the fuel injector, for example. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these sensors go bad you will get codes on the diagnostic scanner which can lead to engine shutdown.

Some of the signs of a failing G28 sensor include an inaccurate rev counter for the gearbox and gears that shift faster than normal, and/or a misfire when you’re in gear. It is possible that the sensor is failing and needs to be replaced if you experience any of these symptoms. The good thing is that they are very cheap and readily available particularly when you’re looking at a Bosch model, like ours. Alternatively, GM’s version of this component is a good option.

5. Tachometer

A failing engine sensor could cause a myriad of issues in your vehicle. It’s an essential component of the transmission of your audi car key cover, as it transmits information to the ECU about how fast or slowly the engine of the car is turning. This sensor can cause the transmission to malfunction and other components of the car to be affected.

The G5 engine speed sensor is located at the outside of the transmission above the flywheel ring gear and transmits a signal to the ECU at pin T55/49 through a grey wire. The ECU uses this signal to control the amount of fuel and boost, and also timig. It also relays it to the G5 Tachometer located in the instrument cluster. You can check the sensor for any failure by checking the continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. It should show approximately 1000 ohms of resistance between these two points. This is a common component across the replacement audi a4 key 80 100 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU, so the best parts could be found in wrecking yards.