The Three Greatest Moments In Audi G28 History How to Replace an Audi G28 Engine Speed Sensor

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

1. Engine Speed Sensor

The sensor is located at the edge of the transmission above the flywheel ring gear the G28 Engine Speed Sensor sends a signal to ECU pin T55/49 through the grey wire. The ECU then uses this information to control the flow of fuel, timig and boost. It also sends a signal to the G5 tachometer inside the instrument cluster.

The sensor is used to connect the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft reached TDC and also the position of the camshaft, in order to activate the spark and injectors.

If this sensor fails to function, the ECU will display a P00160 error message. This means that the Crank Shaft is out of sync with the Intake Camshaft. It could also indicate the possibility of a chain stretch or jumped chain link in the upper timing chain. The code won't show without the additional information provided by other sensors (G4 or G40).

It's a bit tricky to test as there are different connector pins, and each has its own functions. The best way to do it is by measuring the resistance between the ECU and the sensor. When the sensor is fully functional, it should read about 1000 ohms. Look for evidence of coolant or oil in the connector bay if you are experiencing issues with this component.

2. Injectors

Yesterday, while accelerating at full speed from the highway paytoll, i experienced an abrupt drop in power like the engine is running out of gas or injectors are not firing any more. I pulled out the spark plugs this morning and found that 3 were soaked with gasoline and the fourth was dry. I put tissue over each hole in the injector and when i start the engine without sparks, the three with gazoline jump out. The 4th one remains shut. I inspected the ground connection on ECU pins 14/55,30/55 and 48/55 i get zero Ohm. 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 works fine when the G28 connected. However, the intermittent misfire problem continues to occur at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature value of that is -49c even after unplugging it. audi key replacement noticed that the oil gauge in the cockpit shows 2 bars but the actual pressure is 0.

I'm not sure what to do, but i believe that i've completely ruled out all other possibilities. But i'm worried that i might have missed something. Let me know If you have any suggestions! TIA!

3. Fuel Pump

The fuel pump in the g28 receives signals from 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 locate an extra in a wrecking shop or a parts store. Testing them is easy - 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 know the speed and position of the crankshaft in order to make a decision about timing of fuel injectors, etc. To accomplish this, it uses a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these go bad you will get codes on the diagnostic scanner that could cause engine shut down.

The signs of a failing G28 sensor are an inaccurate gearbox rev counter the gears are shifting faster than normal and/or a misfire when you're in gear. It is possible that the sensor is failing and requires to be replaced if you notice any of these signs. They're inexpensive and easy to locate especially when they're a Bosch unit like ours. Alternately, the GM version of this part is also a good option.

5. Tachometer

A malfunctioning engine sensor can cause a number of problems within your vehicle. It's an essential component of the transmission of your Audi since it sends information to the ECU about how fast or slow the car's engine is turning. This sensor can cause the transmission to fail and other car components to be affected.

The G5 engine sensor is located at the edge of the transmission, over the flywheel ring. It sends a signal via gray wire to ECU pin T55/49. The ECU uses this signal to regulate fuel and boost, and also to timigrate. It also transmits it to the G5 Tachometer in instrument cluster. You can test the sensor for any failure by checking the continuity between it and the tachometer. You can also check continuity between ECU pin T55/49 and the instrument cluster connection on pin T6a/1 (trace [79trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. audi advanced key should observe approximately 1000 ohms resistance between those points. This part is common across the Audi 80-100-200-RS2 model, ranging from the 1985 MC up to the 1997 UrS An and 1995 RS2 DU You may also find good ones in wrecking yards.