Are You Responsible For An Audi G28 Budget? 10 Terrible Ways To Spend Your Money 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 on the outside of the transmission over the flywheel gear. It transmits a signal to the ECU via a grey wire (T55/49), then to the tachometer within the instrument cluster.

1. Engine Speed Sensor

The grey wire is situated at the edges of the transmission, just above the flywheel ring. The sensor transmits an electrical signal through the grey wire to pin T55/49. The ECU then uses this information to control the flow of fuel, timig and boost. It also sends an indication to the G5 Tachometer in instrument cluster.

The sensor is used to connect with the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft reached TDC and also the location of the camshaft so that it can activate the spark and injectors.

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

Testing is a bit challenging as there are two different pins for the connector and they have different functions however the best way to test it is by measuring resistance between the sensor and the ECU. It should read around 1000 ohms if the sensor is at full operation. Examine for evidence of coolant or oil in the connector bay if there are issues with this part.

2. Injectors

Yesterday, when i was accelerating to the fullest speed from highway paytoll, I experienced massive power loss like the engine is out of gas or the injectors are not firing anymore. This morning i pull out the spark plugs. Three were drenched with gazoline the fourth was dry. When I start the engine without sparks i put tissue on top of each injector hole, the 3 drenched with gazoline leap out, however the 4th one stays shut. I tested the ground connection of ECU pins 14,30, and 48/55. I found 0ohm. Therefore, i think the issue is somewhere else.


I also tried to reset PID 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 problem still occurs at higher RPM. spare audi key The Keylab (G62) even when it is unplugged, shows temperatures of -49c. 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 ruled everything else out. But i am afraid i might have missed something. Let me know if you have any ideas! TIA!

3. Fuel Pump

The fuel pump in the g28 can be activated by a signal sent from the RPM sensor. The GM-style transmitter is identical to the G4 and both are used in the 80 100 200, UrS and RS2 cars so you can easily find one at a wrecking yard or in a local parts store. Testing them is easy - put your DMM in resistance mode and measure between pins 1 (with the bump on the connector's side up) and 2 (2nd from 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 has to be aware of the speed and position of the crankshaft in order to make a decision about fuel injector timing etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you have a problem with either of these sensors, the diagnostic scanner will display codes that could lead to the engine shutting down.

A failing G28 sensor can cause an inaccurate speed counter for the gearbox or a gearbox that shifts faster than normal, or an unfire when in the gear. If you have any of these issues, it is likely your sensor is failing and needs replacing. The good thing is that they are quite affordable and easy to find particularly when you're looking at an Bosch sensor, which is what ours are. Alternatively, the GM version of this part is also a great option.

5. Tachometer

A malfunctioning engine sensor can cause a myriad of issues in your car. It's an essential component of your Audi's transmission, as it sends information to the ECU about how fast or slow the vehicle's crankshaft is rotating. This sensor could cause the transmission to fail and other car components to be affected.

The G5 engine sensor is located near the edge of the transmission, over the flywheel ring. It transmits a signal via gray wire to ECU pin T55/49. The ECU is then able to process the signal to control the flow of fuel, timig and boost as well as transmitting it to the G5 Tachometer located 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 [79trace [79]) and between pin T6a/1 as well as pin T26a/12. It should show approximately 1000 ohms resistance between those points. This is a common part across the Audi 80 100, 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU so good ones could be available in wrecking yards.