How to Replace an Audi G28 Engine Speed Sensor

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

1. Engine Speed Sensor

The grey wire is situated on the outside of the transmission, directly above the flywheel ring. The sensor sends a signal via the grey wire to pin T55/49. The ECU uses this information to regulate fuel and boost. It also sends an indication 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 is TDC and where the camshaft is so it can trigger spark and injectors in the right way.

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

Testing is a bit tricky as there are two different pins for the connector and they have different functions but the best method to test it is to measure resistance between the sensor and the ECU. It should read around 1000 ohms when the sensor is at full operation. If you are having problems with this component, look for signs of coolant or oil in the connector bay.

2. Injectors

Yesterday, while accelerating from the highway paytoll at full speed I noticed a significant reduction in power. It was like the engine had run out of gas. Or, my injectors were not firing. I pulled out the spark plugs this morning, 3 were soaked with gasoline and the fourth was unclean. I put a piece of tissue over each injector hole, and when I start the engine with no sparks, the three that have gazoline pop right out. The fourth one remains closed. I inspected the ground connection on ECU pins 14/55,30/55 and 48/55 I got zero ohm. I'm assuming that the issue is in another location.

I also tried to reset the PID but without success. The car key cover audi will start when the G28 is unplugged, and it is running fine with the G28 plugged in. However the intermittent misfire issue still occurs at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature value of -49c, even if I unplug it. Also i noticed that the gauge for oil pressure in the cockpit shows 2 bar while the actual pressure is 0.0 when i rev the engine.

I don't know what to do. I feel like i've pretty much all other possibilities out. But i am afraid i might have missed something. If anyone has any suggestions, please let me know! TIA!

3. Fuel Pump

The fuel pump in the g28 receives signals from the RPM sensor. The GM-style transmitter is the same as the G4 and both function in the 80, 100 200, UrS and RS2 cars which is why you can easily locate one at a salvage yard or in a local parts store. It is simple to test them - just put your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump at the connector's end facing up). They must be infinite ohms.

4. ECU

The ECU of our 20vt turbo (3B AAN ABY ADU) engines must be aware of the position and speed of the crankshaft in order to make a decision about fuel injector timing, etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these go wrong, you will receive codes on the diagnostic scanner that can lead to engine shutdown.

A malfunctioning G28 sensor could cause an inaccurate speed counter for your gearbox, a gearbox that shifts more quickly than normal, or a misfire while in the gear. It is likely that your sensor is failing and needs to be replaced if you encounter any of these signs. The good thing is that they are very affordable and easily accessible particularly in the case of the Bosch model, which is what ours are. You can also choose the GM version of this part is also a good choice.

5. Tachometer

A damaged engine sensor could cause a number of problems in your vehicle. It's a vital component of the Audi's transmission since it relays information to the ECU about how the car's crankshaft is turning. This sensor could cause the transmission to fail and other components of the car to be affected.

The G5 engine sensor is located at the edge of the transmission, over the flywheel ring. It sends an electrical signal through gray wire to ECU pin T55/49. The ECU is then able to process this signal to control fuel, timig, and boost and then transmitting it to the G5 Tachometer located in the instrument cluster. You can test for sensor failure by checking continuity from the sensor to the tachometer. Additionally, you can check continuity between pin 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 an average resistance of 1000 ohms between these two points. This is the same across the audi tt key fob key fob replacement cost of audi key replacement (please click the following webpage) 80-100-200-RS2 range, from the 1985 MC up to the 1997 UrS AN and the 1995 RS2 DU, so you might find good ones in wrecking yards.