14 Smart Ways To Spend Your Leftover Audi G28 Budget How to Replace an Audi G28 Engine Speed Sensor

Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. The sensor is located at the top of the transmission, above the flywheel ring gear. It transmits a signal to the ECU through an uncolored wire T55/49, then to the tachometer on the instrument cluster.

1. Engine Speed Sensor

The grey wire is located on the edge of transmission, just above the flywheel ring. The sensor sends a signal via 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 signals to the G5 tachometer inside the instrument cluster.

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

If this sensor fails the ECU will throw the P00160 error, which means the Crank Shaft and Intake Camshaft are out of sync and possibly indicating the chain stretching or a jump link on the upper timing chain. However, the error code won't be displayed on its own without additional information from other sensors (G4 and G40).

It can be a bit difficult to test as there are several connector pins, and they all have different functions. The best method for doing this is by measuring the resistance between the ECU and the sensor. When the sensor is operational, it should be reading approximately 1000 ohms. If you're experiencing issues with this sensor, look for evidence of oil or coolant in the connector bay.

2. Suggested Webpage , when accelerating from highway paytoll at full speed I noticed a significant decrease in power. It was as if the engine had run out of gas. Or, my injectors were not firing. I took out the spark plugs this morning, 3 were soaked with gasoline and the fourth was unclean. When i crank the engine without sparks, I put a piece of tissue on the top of each of the injector holes, the 3 drenched with gazoline jump out but the 4th stays shut. I tested the ground connection on ECU pins 14/55,30/55 and 48/55 I get zero Ohm. I think the issue is somewhere else.

I also tried to reset the PID without success. The car will start when the G28 is unplugged, and it works fine when the G28 connected. However, the intermittent misfire problem persists at higher RPM. The coolant sensor (G62) even when unplugged, still shows temperatures of -49c. I also noticed that the oil gauge in the cockpit shows 2 bars while the actual pressure is 0.

I'm not certain what to do, as i believe that i've eliminated everything else. I'm concerned that i may have missed something. If anyone has any ideas please share them! TIA!

3. Fuel Pump


The fuel pump in the g28 receives a signal from the RPM sensor. The GM-style sender is identical to the G4 and both function in the 80, 100 200, UrS and RS2 cars which is why you can easily locate one at a wrecking yard or in a local parts store. Testing them is easy to do - just put your DMM in resistance mode and take measurements between pins 1 (with the bump on the connector end 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 has to be aware of the speed and position of the crankshaft to make decisions regarding timing of the fuel injectors, etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If you are experiencing issues with either of these sensors, the diagnostic scanner will show codes that could lead to an engine shutdown.

A failing G28 sensor could result in an inaccurate speed counter for the gearbox or a gearbox that shifts faster than normal, or a misfire in gear. If you are experiencing any of these problems, it is most likely that your sensor is going bad and should be replaced. The good news is that they are quite affordable and readily available particularly if you're looking at a Bosch sensor, which is what we have. If you prefer, GM's version of this part would be an excellent choice.

5. Tachometer

A failing engine speed sensor could be the reason behind a slew of issues in your vehicle. It is an important part of the transmission of your Audi, as it transmits information to the ECU on how fast or slow the car's engine is turning. If the sensor fails, it can cause problems for the transmission, as well as the other car's components.

The G5 engine speed sensor is located on the edge of the transmission just above the flywheel ring gear. It sends a signal to the ECU at pin T55/49 via a grey wire. The ECU uses this signal to regulate the flow of fuel and boost as well as timig. It also relays it to the G5 Tachometer in instrument cluster. You can test for sensor failure by examining the continuity of the sensor to the tachometer. You can also examine the continuity between pins T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]), and between pin T6a/1 and pin T26a/12. You should see approximately 1000 ohms of resistance between those points. This part is common across the Audi 80-100-200-RS2 series, starting from the 1985 MC all the way up to the 1997 UrS AN and 1995 RS2 Du So, you may find some good ones in wrecking yards.