The Three Greatest Moments In Audi G28 History

How to Replace an replacement audi car key G28 Engine Speed Sensor

In this video, Charles the Humble Mechanic demonstrates how to replace the G28 engine speed sensor. The sensor is situated on the edge of the transmission, above the flywheel ring gear. It transmits a signal the ECU via a grey 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, just above the flywheel ring. The sensor sends a signal via the grey wire to pin T55/49. The ECU then uses this information to control fuel, timig and boost. It also sends an indicator to the G5 Tachometer within the instrument cluster.

The sensor is used as a reference for comparing with the G40 Camshaft Position Sensor. The ecu must be aware when the crankshaft is TDC and the location of the camshaft so it can start spark and injectors according to the situation.

If this sensor fails, replacement audi A4 key the ECU will display the P00160 error, which means the Crank Shaft and Intake Camshaft are not in sync and possibly indicating the chain stretching or a jump link on the upper chain of timing. The code won't appear without the additional information provided by other sensors (G4 or G40).

It's a bit tricky to test because there are various connector pins, and they all have different functions. The most effective method to test it is to measure the resistance between the ECU and the sensor. It should read around 1000 ohms if the sensor is at full operation. Examine for signs of coolant or oil in the connector bay if you have problems with this part.

2. Injectors

Yesterday, as i was accelerating off the highway paytoll at full speed I noticed a massive decrease in power. It was as if the engine had run out of gas. Or, my injectors were not firing. I took out the spark plugs this morning, three were soaked in gasoline, and the fourth was unclean. I put tissue over each injector hole and when I turn the engine on without sparks, the three that have gazoline pop right out. The fourth one remains shut. I checked the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ i get 0ohm. I assume that the problem is in another location.

I also tried to reset the PID without success. The car is able to start when the G28 is not plugged in and it runs perfectly when it is plugged in however it has intermittent misfire issues at higher RPM. The coolant temperature sensor (G62) shows the wrong temperature of -49c even when i unplug it. I also noticed that the oil gauge in the cockpit shows 2 bar but the actual pressure is zero.

I'm not certain what to do, i think i've pretty much ruled out everything else. But i'm worried that I might have missed something. Let me know If you have any suggestions! TIA!

3. Fuel Pump

The fuel pump of the g28 gets a signal from the RPM sensor. The GM-style sensor is identical to the G4 and repairer both are used in the 80 100 200, UrS and RS2 cars which is why you can easily locate one at a junkyard or at a parts store. It is simple to test them - simply switch your DMM into resistance mode and test the distance between pins 1 and 2 (with the bump at the connector end facing upwards). They should be infinite Ohms.

4. ECU

The ECU of our 20vt turbo (3B AAN ABY ADU) engines requires to be aware of the position and speed of the crankshaft to determine timing of fuel injectors, etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you encounter a problem with either of these sensors, the diagnostic scanner will display the codes that could trigger the engine shutting down.

Some of the symptoms of a malfunctioning G28 sensor are an inaccurate gearbox rev counter, gears shifting quicker than normal and/or misfiring when in gear. If you are experiencing any of these issues it is most likely that your sensor is deteriorating and needs replacing. The good thing is that they are very cheap and easily accessible particularly in the case of the Bosch model, which is what ours are. Alternately, GM's version this component is a good option.

5. Tachometer

A malfunctioning engine sensor can cause a number of problems within your vehicle. It is a crucial part of the Audi's transmission because it communicates to the ECU about how fast or slow the vehicle's crankshaft is turning. This sensor can cause the transmission to fail and other components of the car to be affected.

The G5 engine speed sensor is located at the outside of the transmission, above the flywheel ring gear. It transmits a signal to the ECU at pin T55/49 through an uncolored wire. The ECU then uses and processes this signal to regulate the flow of fuel, timig and boost and then sends it on to the G5 tachometer in the instrument cluster. You can check the sensor for any failure by checking the continuity between it and the tachometer. You can also check continuity between ECU pin T55/49 and the instrument cluster connection on 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 standard part that is found across the replacement audi a3 key 80 100 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU, so the best parts could be found in wrecking yards.