How to Replace an audi keys replacement G28 Engine Speed Sensor

Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. This sensor is located near the edges of the transmission just above the flywheel ring gear. It transmits a signal to the ECU via the grey wire (T55/49) which is then sent to the tachometer 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 then utilizes this information to regulate fuel, timig and boost. It also sends an indication to the G5 Tachometer in instrument cluster.

The sensor serves as a reference to correlate with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft reached TDC and also the location of the camshaft to trigger the spark and injectors.

If this sensor fails to function, the ECU will display a P00160 error code. This indicates that the Crank Shaft is not in alignment with the Intake Camshaft. It could also indicate a chain stretch or a jump in the chain link of the upper chain of timing. The code won't show without the additional information provided by other sensors (G4 or G40).

It's a bit tricky to test as there are several pins on the connector and they all have different functions. The best method for doing this is to measure the resistance between the ECU and the sensor. When the sensor is functional, it should read approximately 1000 ohms. Examine for signs of coolant or oil in the connector bay if you have issues with this part.

2. Injectors

Yesterday, as i was accelerating off the highway paytoll at maximum speed, i noticed a huge reduction in power. It was like the engine was running out of gas. Or, my injectors weren't firing. Today, i pulled out the spark plugs. Three were drenched in gazoline, the 4th one was dry. I put tissue over each injector hole and when i start the engine with no sparks, the 3 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 get 0ohm. I think the issue is elsewhere.

I also tried to reset the PID with no success. The car will start when the G28 is unplugged, and it runs fine with the G28 connected. However the intermittent misfire issue continues to occur at higher RPM. The temperature sensor for coolant (G62) shows the wrong temp value that is -49c even after unplugging it. I also noticed that the gauge for oil pressure in the cockpit shows 2 bar when the actual pressure is 0.0 if i crank up the engine.

I don't know what to do. I believe that I've ruled everything else out. I'm worried that i might have missed something. If anyone has any suggestions, please share them! TIA!

3. Fuel Pump

The fuel pump in the g28 gets a signal from the RPM sensor. The GM-style transmitter is identical to the G4 sender and works on the 80,100,200, UrS, and RS2 vehicles. It is easy to find the audi spare key cost in a salvage shop or parts store. It is simple 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 must be infinite ohms.

4. ECU

The ECU in our 20vt turbo (3B AAN ABY ADU) engines requires to be aware of the speed and position of the crankshaft in order to make a decision about 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 go wrong, you will receive codes on the diagnostic scanner that can lead to engine shutdown.

The signs of a malfunctioning G28 sensor include an inaccurate gearbox rev counter the gears are shifting faster than normal, and/or a misfire when in gear. If you are experiencing any of these issues it is most likely that your sensor is failing and should be replaced. They're inexpensive and easy to locate, especially when they're an Bosch unit like ours. Alternatively, GM's version of this part is an option.

5. Tachometer

A malfunctioning engine speed sensor could be the reason behind a slew of problems in your car. It is an important part of the transmission in your replacement audi key cost because it relays information to the ECU about how fast or slowly the car's engine is turning. This sensor can cause the transmission to malfunction and other components of the car to be affected.

The G5 engine speed sensor is situated on the outside of the transmission, above the flywheel ring gear and transmits a signal to the ECU at pin T55/49, via an uncolored wire. The ECU utilizes this signal to control the amount of fuel and boost, and also to timigrate. It also relays it to the G5 Tachometer located in the instrument cluster. You can check the sensor for any failure by checking the continuity between it and the tachometer, between ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. You should observe around 1000 ohms of resistance between those points. This is the same across the audi connect key 80-100-200-RS2 model, ranging beginning with the 1985 MC and up to the 1997 UrS An and 1995 RS2 Du So, you may find good ones in wrecking yards.