How to Replace an audi keyless go G28 Engine Speed Sensor

Charles the Humble Technician shows you how to replace the G28 Engine Speed Sensor. This sensor is situated near the transmission's edge over the flywheel 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

Located on the edge of the transmission above the flywheel ring gear the G28 Engine Speed Sensor sends a signal to ECU pin T55/49 using an uncolored wire. The ECU uses this information to regulate boost and fuel. It also sends an alert to the G5 Tachometer located in the instrument cluster.

The sensor is used to correlate with the G40 Camshaft position Sensor. The ecu must be aware when the crankshaft is TDC and where the camshaft is located so that it can activate spark and injectors accordingly.

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

It's a bit tricky to test as there are different connector pins, and each one has different functions. The best way to do it is by measuring the resistance between the ECU and the sensor. It should read about 1000 ohms if the sensor is in full operation. If you're experiencing issues with this part, check for signs of oil or coolant in the connector bay.

2. Injectors

Yesterday, while accelerating at full speed from the highway paytoll i had an abrupt drop in power like the engine is out of gas or injectors are not firing anymore. In the morning, i removed the spark plugs, three were soaked with gazoline and the fourth was dry. I put a piece of tissue over each hole in the injector and when I start the engine with no sparks, the ones that have gazoline pop right out. The 4th one remains shut. I checked the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ i get 0ohm. I'm assuming the issue is in another place.

I also tried to reset the PID but with no luck. The car key cover audi car key replacement cost (this site) can start when the G28 is unplugged and is running fine when it is plugged in but it still is experiencing intermittent misfires at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature of -49c, even if I unplug it. I also noticed that the oil gauge in the cockpit shows 2 bars but the actual pressure is 0.

I'm not sure what to do. I believe that I've all other possibilities out. I'm worried that i might have missed something. If anyone has any ideas please let me know! TIA!

3. Fuel Pump

The fuel pump of the g28 receives signals from 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 salvage yard or in a local parts store. It is simple to test them by putting your DMM in resistance mode and measure between pins 1 (with the bump on the connector end up) and 2 (2nd from the left on the black connector's end). They must be infinite Ohms.

4. ECU

The ECU in our 20vt turbo (3B AAN ABY) engines must know the position and speed of the crankshaft in order to make a decision about fuel injector timing, etc. To accomplish this, it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you are experiencing issues with either of these sensors, the diagnostic scanner will show the codes that could trigger the engine shutting down.

The signs of a malfunctioning G28 sensor include an inaccurate rev counter in the gearbox the gears are shifting faster than normal, and/or a misfire when you are in gear. It is possible that your sensor is failing and requires to be replaced if you experience any of these symptoms. They are cheap and easy-to-find particularly when they're an Bosch model like ours. You can also choose the GM version of this component is also a good option.

5. Tachometer

A failing engine sensor could cause a variety of issues in your vehicle. It's an essential component of your audi advanced key's transmission, since it relays information to the ECU about how fast or slow the vehicle's crankshaft is rotating. If this sensor fails, it can 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 signals via gray wire to ECU pin T55/49. The ECU is then able to process this signal to regulate fuel, timig, and boost, and also 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. Also, you can 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 is a standard part that is found across the replacement audi a4 key 80, 100 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU. Good ones could be available in wrecking yards.