The 10 Scariest Things About Audi G28

How to Replace an Audi G28 Engine Speed Sensor

Charles the Humble Technician teaches how to replace the G28 Engine Speed Sensor. This sensor is located near the edges of the transmission, above the flywheel ring gear. It sends a message to the ECU through a grey wire T55/49, then to the tachometer located on the instrument cluster.

1. Engine Speed Sensor

Located on the edge of the transmission, above the flywheel ring gear G28 Engine Speed Sensor sends a signal to ECU pin T55/49 using the grey wire. The ECU then utilizes this information to regulate the flow of fuel, timig and boost. It also sends an alert to the G5 Tachometer within the instrument cluster.

The sensor is used as a reference point to connect with the G40 Camshaft Position Sensor. The ecu must be aware when the crankshaft is TDC and where the camshaft is located so that it can activate spark and injectors according to the situation.

If this sensor fails, the ECU will display the P00160 error, which means the Crank Shaft and Intake Camshaft are not in sync and could indicate the chain is stretched or a jump link on the upper timing chain. However, the error code won't appear on its own, without additional information from other sensors (G4 and G40).

Testing is a bit challenging as there are two different connector pins, and they have different functions however the best method to test it is to measure resistance between the sensor and the ECU. If the sensor is operational, it should read approximately 1000 ohms. Examine for signs of coolant, or oil in the connector bay if you have issues with this part.

2. Injectors

Yesterday accelerating full speed from highway paytoll i had a big cut in power like the engine is out of gas or the injectors are not firing at all. Today, i pulled out the spark plugs. Three were drenched in gazoline, the fourth one was dry. I put tissue over each injector hole, and when I start the engine without sparks, the ones 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 elsewhere.

I also tried to reset the PID with no success. The car will start when the G28 is disconnected, but it runs fine with the G28 connected. However the intermittent misfire issue continues to occur at higher RPM. The coolant temperature sensor (G62) shows the wrong temperature value of that is -49c even after unplugging it. I also noticed that the oil gauge in the cockpit shows 2 bar while the actual pressure is zero.

I'm not sure what to do. I feel like i've pretty much ruled everything else out. I'm concerned that i may have missed something. Please let me know If you have any suggestions! TIA!

3. Fuel Pump

The fuel pump in the g28 receives a signal from the RPM sensor. The GM-style transmitter functions similarly to the G4 sender and works on the 80,100,200, UrS, and audi tt key fob not working RS2 vehicles. You can easily locate a spare in a wrecking shop or a parts store. Testing them is easy to do - just put your DMM in resistance mode and measure between pins 1 (with the bump on the connector's side up) and 2 (2nd from the left on the black connector's end). They should be infinite Ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY, and ADU) engines are equipped with an ECU that needs to know the speed and position of the crankshaft to make decisions about fuel injector timing etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If you encounter a problem with either of these sensors, the diagnostic scanner will show the codes that could trigger an engine shutdown.

Some of the signs of a failed 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 probable that the sensor is failing and needs to be replaced if you encounter any of these signs. The good thing is that they are quite affordable and easy to find particularly in the case of the Bosch unit like ours. Alternatively, GM's version of this part is an excellent choice.

5. Tachometer

A failing engine sensor could cause a number of problems within your vehicle. It is a crucial part of your audi tt key fob not working's transmission, because it communicates to the ECU about how fast or slow the car's crankshaft is rotating. When this sensor fails, it can disrupt the performance of the transmission as well as the other car's components.

The G5 engine sensor is located at the edge of the transmission, over the flywheel ring. It transmits an electrical signal through an uncolored wire to the ECU pin T55/49. The ECU uses this signal to regulate fuel and boost, and also timig. It also relays it to the G5 Tachometer in instrument cluster. You can test the sensor for failure by examining the continuity between it and the tachometer, between ECU pin T55/49 and the instrument cluster connection on pin T6a/1 (trace [79trace [79]) and between pin T6a/1 and audi tt key fob not working the instrument cluster pin T26a/12. There should be an average resistance of 1000 ohms between these points. This is a common component across the audi a5 key fob 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.