How to Replace an audi remote key G28 Engine Speed Sensor

In this video, Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. The sensor is located on the edge of the transmission just above the flywheel ring gear. It transmits a signal to the ECU via an uncolored wire T55/49, then to the tachometer on the instrument cluster.

1. Engine Speed Sensor

The grey wire is located at the edges of the transmission, just above the flywheel ring. The sensor sends a signal via the grey wire to pin T55/49. The ECU utilizes this information to control fuel and boost. It also sends an indicator to the G5 Tachometer in instrument cluster.

The sensor is used as a reference to correlate with the G40 Camshaft Position Sensor. The ecu needs to know when the crankshaft is TDC and the location of the camshaft so it can start spark and injectors in the right way.

If this sensor fails, the ECU will display a P00160 error code. This means that the Crank Shaft is not in alignment with the Intake Camshaft. It could also be a sign of a chain stretch or a jumped chain link in the upper chain. However, the error code won't appear on its own, without additional information from other sensors (G4 and G40).

It is a little tricky to test because there are various connector pins, and audi key Fobs 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 operational, it should be reading approximately 1000 ohms. Look for evidence of coolant or oil in the connector bay if you are experiencing problems with this part.

2. Injectors

Yesterday, while accelerating from the highway paytoll at maximum speed I noticed a massive decrease 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 and found that 3 were drenched in gasoline and the 4th was dry. I placed a tissue over each hole in the injector and when I turn the engine on without sparks, the three with gazoline jump out. The fourth one remains shut. I tested the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I get zero Ohm. I think the issue is in another location.

I also tried to reset the PID with no success. The car is able to start if the G28 is not plugged in and runs fine when it is connected however it is experiencing intermittent misfires at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature of that is -49c even after unplugging it. Also i noticed that the oil pressure gauge in the cockpit is showing 2 bar while the actual pressure is 0.0 when i rev the engine.

I'm not sure what to do, i believe that i've completely ruled out all other possibilities. But i am afraid I might have missed something. If anyone has suggestions, please let me know! TIA!

3. Fuel Pump

The fuel pump on the g28 is activated by a signal sent from the RPM sensor. The GM-style transmitter 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 junkyard or in a local parts store. It is easy to test them - just switch your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump at the connector's end facing up). They should be infinite ohms.

4. ECU

The ECU in our 20vt turbo (3B AAN ABY) engines must know the position and speed the crankshaft to determine timing of fuel injectors, etc. In order to do this it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these sensors go bad you will get codes on the diagnostic scanner that can cause the engine to shut down.

A failing G28 sensor could result in an inaccurate speed counter key for audi the gearbox, a gearbox that shifts faster than normal, or a misfire in the gear. If you experience any of these problems, it is most likely that your sensor is deteriorating and requires replacement audi car key. They're cheap and easy to find, especially if they're an Bosch model like ours. Alternately, GM's version this part would be an excellent choice.

5. Tachometer

A faulty engine speed sensor could be the cause of many issues in your vehicle. It is a crucial part of the audi replacement car keys's transmission because it communicates to the ECU about how fast or slow the car's crankshaft is spinning. When this sensor fails, it will disrupt the performance of the transmission as well as the other car's components.

The G5 engine speed sensor is located at the outside of the transmission just above the flywheel ring gear. It sends a signal directly to the ECU at pin T55/49 through an uncolored wire. The ECU then processes this signal to control fuel, timig and boost and then sends it on to the G5 Tachometer located in the instrument cluster. You can test the sensor for any failure by checking the continuity between it and the tachometer, between ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. It should show around 1000 ohms of resistance between those points. This is the same across the Audi Keys Replacement cost 80-100-200-RS2 model, ranging from the 1985 MC all the way up to the 1997 UrS An and 1995 RS2 DU So, you may find them in wrecking yards.