How to Replace an audi a3 spare key G28 Engine Speed Sensor

Charles the Humble Technician teaches you how to replace the G28 Engine Speed Sensor. This sensor is located at the top of the transmission above the flywheel ring gear. It sends a message to the ECU via the grey wire T55/49 and then to the tachometer located on the instrument cluster.

1. Engine Speed Sensor

The sensor is located at the edge of the transmission above the flywheel ring gear the G28 Engine Speed Sensor sends signals to ECU pin T55/49 using a grey wire. The ECU then utilizes this information to regulate fuel, timig and boost. It also sends an indication to the G5 Tachometer located in the instrument cluster.

The sensor is used as a reference point to connect 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 start spark and injectors according to the situation.

If this sensor fails, the ECU will display an error code P00160. This indicates that the Crank Shaft is out of sync 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. However, the code won't be displayed on its own without additional information from other sensors (G4 and G40).

Testing can be a bit difficult as there are two different pins for the connector and they perform different functions however the best method of testing it is by measuring resistance between the sensor and the ECU. It should read around 1000 ohms when the sensor is at full operation. Check for signs of coolant or oil in the connector bay if there are issues with this component.

2. Injectors

Yesterday accelerating full speed from highway paytoll, i experienced a big cut in power like the engine is out of gas or injectors are not firing anymore. This morning i pull out the spark plugs, 3 were soaked with gazoline and the fourth one was dry. When I crank the engine without sparks i put tissue on top of each injector hole and the 3 that were drenched in gazoline leap out, however the 4th one stays shut. I tested the ground connection of ECU pins 14,30 and 48/55. I got zero ohm. I assume that the problem is elsewhere.

I also tried to reset the PID without success. The car can start if the G28 is unplugged and it runs perfectly when it is connected but it still is experiencing intermittent misfires at higher RPM. The temperature sensor for 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 bar when the actual pressure is zero.

I'm not sure what to do, but i believe that i've eliminated everything else. But i am afraid I may have missed something. If anyone has any ideas please share them! TIA!

3. Fuel Pump

The fuel pump in the g28 gets a signal from the RPM sensor. The GM-style transmitter functions similarly to the G4 sender and works on the 80,100,200, UrS, and RS2 vehicles. You can easily find a spare in a wrecking shop or parts store. It is simple to test them - simply put your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump at the connector end facing up). They must be infinite Ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY and ADU) engines are equipped with an ECU that needs to be aware of the speed and position of the crankshaft in order to make decisions regarding timing of the fuel injector, for example. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If either of these goes badly, you will see codes on the diagnostic scanner which can cause the engine to shut down.

Some of the signs of a failed G28 sensor include an inaccurate rev counter for the gearbox, gears shifting quicker than normal, and/or a misfire when you're in gear. If you have any of these issues, it is most likely that your sensor is failing and needs replacing. They are cheap and easy-to-find especially if they're an Bosch sensor like ours. 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 problems in your car key replacement audi. It's an essential component of your audi a3 spare key's transmission, since it relays information to the ECU about how fast or slow the vehicle's crankshaft is turning. This sensor can cause the transmission to malfunction and other components in the car to be affected.

The G5 engine sensor is located at the edge of transmission, above the flywheel ring. It sends an electrical signal through gray wire to ECU pin T55/49. The ECU utilizes this signal to regulate fuel and boost, and also timig. It also sends it to the G5 Tachometer inside the instrument cluster. You can check the sensor for failure by checking continuity between it and the tachometer, between ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. You should detect an average resistance of 1000 ohms in these areas. This is a standard component across the audi replacement key cost uk smart key replacement audi a4 key - https://tagoverflow.stream/, 80, 100 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU so good ones could be available in wrecking yards.