How to Replace an replacement key audi G28 Engine Speed Sensor

In this video, Charles the Humble Mechanic demonstrates how to replace the G28 engine speed sensor. The sensor is located on the outside of the transmission, above the flywheel gear. It transmits a signal to the ECU via a grey wire (T55/49) which is then sent to the tachometer located in the instrument cluster.

1. Engine Speed Sensor

The grey wire is situated on the outside of the transmission, 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 inside the instrument cluster.

The sensor serves as a reference to correlate with the G40 Camshaft Position Sensor. The ecu needs to know when the crankshaft has reached TDC, and the position of the camshaft, to trigger the spark and injectors.

If this sensor fails the ECU will display an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are out of sync and possibly indicating the chain stretching or a jump link on the upper chain of timing. The code won't show without the additional information supplied by other sensors (G4 or G40).

Testing is a bit challenging since there are two pins for the connector and they have different functions but the most effective way to test it is by measuring resistance between the sensor and the ECU. It should read approximately 1000 ohms when it is operating at its maximum. If you're having issues with this component, look for signs of coolant or oil in the connector bay.

2. Injectors

Yesterday, when i was accelerating to the fullest speed from highway paytoll, i experienced massive power loss like the engine is running out of gas or the injectors aren't firing at all. This morning i pull out the spark plugs, 3 were drenched in gazoline, the 4th one was dry. When I start the engine, there are no sparks i put tissue on the top of each hole in the injector and the 3 that were drenched in gazoline leap out, however the 4th stays shut. I tried to test the ground connections of ECU pins 14,30, and 48/55. I found zero ohm. I'm assuming that the issue is in another location.

I also tried to reset PID but without success. The car can start when the G28 is unplugged and audi car Key replacement runs fine when it is connected however it has the intermittent misfire issue at higher RPM. The coolant temperature sensor (G62) shows the wrong temp value -49c, even if I unplug it. I also noticed that the gauge for oil pressure in the cockpit shows 2 bar, whereas the actual pressure is 0.0 when i rev the engine.

I'm not sure what to do, as i think i've pretty much completely ruled out all other possibilities. But i'm worried that I may have missed something. Let me know should you have any suggestions! TIA!

3. Fuel Pump

The fuel pump in the g28 is activated by a signal by the RPM sensor. The GM-style transmitter is identical to the G4 and they both work 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. Testing them is easy by putting your DMM in resistance mode and take measurements between pins 1 (with the bump on the connector end up) and 2 (2nd from left on the black end of the connector). They must be infinite Ohms.

4. ECU

The ECU in our 20vt turbo (3B AAN ABY) engines must be aware of the speed and position of the crankshaft to determine timing of fuel injectors, etc. To do this, it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you are experiencing issues with either one of these, the diagnostic scanner will show the codes that could trigger an engine shut down.

A failing G28 sensor could result in an inaccurate speed counter for the gearbox or a gearbox that shifts more quickly than normal, and/or an unfire when in the gear. It is probable that the sensor is failing and needs to be replaced if you experience any of these symptoms. They are cheap and easy-to-find particularly when they're a Bosch sensor like ours. If you prefer, GM's version of this part would be a good option.

5. Tachometer

A failing engine speed sensor could be the cause of numerous issues in your car. It's a vital component of the audi car key replacement cost's transmission as it sends information to the ECU about how the car Key Cover audi's crankshaft is turning. If the sensor fails, it could disrupt the performance of the transmission, as well as the other car's components.

The G5 engine sensor is located at the outskirts of the transmission, just above the flywheel ring. It transmits a signal via an uncolored wire to the ECU pin T55/49. The ECU then processes the signal to control fuel, timig, and boost as well as sends it on to the G5 tachometer in the instrument cluster. You can check the sensor for failure by checking continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. You should see an average resistance of 1000 ohms between these two points. This is a common feature across the replacement audi a4 key 80-100-200-RS2 range, from the 1985 MC up to the 1997 UrS AN and 1995 RS2 DU, so you might find them in wrecking yards.