How to Replace an Audi 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 transmits a signal the ECU via an uncolored wire (T55/49) which is then sent to the tachometer in the instrument cluster.

1. Engine Speed Sensor

The grey wire is situated at the edges of the transmission, above the flywheel ring. The sensor sends an electrical signal through the grey wire to pin T55/49. The ECU then uses this information to control the boost, fuel, and timig. It also sends an indication to the G5 tachometer in the instrument cluster.

The sensor serves as a reference for comparing 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 activate spark and injectors in the right way.

If this sensor fails, the ECU will show a P00160 code which means the Crank Shaft and Intake Camshaft are not in sync and could indicate the chain is stretched or a jump link on the upper timing chain. However, the error code won't be displayed on its own without additional information from other sensors (G4 and G40).

Testing can be a bit difficult since there are two connector pins, and they serve different purposes but the most effective way to test it is to measure the resistance between the sensor and the ECU. When the sensor is fully operational, it should read around 1000 ohms. If you're experiencing issues with this sensor, look for evidence of coolant or oil in the connector bay.

2. Injectors

Yesterday, as i was accelerating off the highway paytoll at full speed I noticed a significant reduction in power. It was as if the engine was running out of gas. Or my injectors were not firing. Today, i pulled out the spark plugs. Three were soaked with gazoline and the 4th one was dry. When I crank the engine, there are no sparks, I put a piece of tissue on top of each injector hole, the 3 drenched with gazoline pop out, but the 4th one stays shut. I tested the ground connection of ECU pins 14,30, and 48/55. I got 0ohm. So i assume the problem is somewhere else.

I also tried to reset the PID but without success. The car will start when the G28 is not plugged in and it runs perfectly when it is plugged in, but still has intermittent misfire issues at higher RPM. The coolant sensor (G62) even if it is not plugged in, shows a temperature of -49c. Also, i more info noticed that the gauge for oil pressure in the cockpit is showing 2 bar while the actual pressure is 0.0 when I crank up the engine.

I'm not sure what to do. I think I've ruled everything else out. I'm afraid i may have missed something. If anyone has suggestions, please share them! TIA!

3. Fuel Pump

The fuel pump of the g28 gets a signal 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 salvage yard or in a local parts store. It is easy to test them: simply put your DMM into resistance mode and test the distance between pins 1 and 2 (with the bump at the connector end facing up). They should 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 to make a decision about fuel injector timing etc. In order to do this it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you encounter a problem with either of these, the diagnostic scanner will display codes that could cause the engine shutting down.

A damaged G28 sensor could result in an inaccurate speed counter for the gearbox and a gearbox which shifts more quickly than normal, or a misfire in the gear. It is likely that your sensor is failing and needs to be replaced if you experience any of these symptoms. The good news is they are very cheap and easy to find particularly if you're looking at the Bosch model, like ours. Alternately, the GM version of this component is also a good choice.

5. Tachometer

A malfunctioning engine speed sensor could be the reason behind a slew of issues in your car. It is a audi lost key replacement crucial part of your Audi's transmission, since it relays information to the ECU about how the car's crankshaft is turning. If this sensor fails, it could disrupt the performance of the transmission, as well as the other car's components.

The G5 engine speed sensor is located on the outside of the transmission just above the flywheel ring gear. It sends a signal to the ECU at pin T55/49, via a grey wire. The ECU is then able to process this signal to control fuel, timig and boost as well as sends read more it on to the G5 tachometer inside the instrument cluster. You can test the sensor for any failure by checking the continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. You lost audi keys should observe approximately 1000 ohms resistance between these two points. This is a typical part across click here the Audi 80, 100 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU. Good ones might be availble in wrecking yards.