Why Nobody Cares About Audi G28

How to Replace an Audi G28 Engine Speed Sensor

In this video, Charles the Humble Mechanic demonstrates how to replace the G28 engine speed sensor. This sensor is situated near the transmission's edge, above the flywheel gear. It sends a message to the ECU via an uncolored wire T55/49, then to the tachometer in the instrument cluster.

1. Engine Speed Sensor

The grey wire is located on the outside of the transmission, just 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 flow of fuel, timig and boost. It also sends an indicator to the G5 Tachometer in instrument cluster.

The sensor is used to link the G40 Camshaft position Sensor. The ecu must 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 display the P00160 error, which means the Crank Shaft and Intake Camshaft aren't in sync and could indicate the chain is stretched or a jump link on the upper chain of timing. The code will not appear without the additional information provided by other sensors (G4 or G40).

It's a bit tricky to test because there are different connector pins, and each one has different functions. The best way to do it is to measure the resistance between the ECU and the sensor. When the sensor is functional, it should read approximately 1000 ohms. Look for signs of coolant or oil in the connector bay if you are experiencing issues with this component.

2. Injectors

Yesterday, as i was accelerating off the highway paytoll at a high speed I noticed a significant drop in power. It was like the engine had run out of gas. Or, my injectors weren't firing. I took out the spark plugs this morning, three were soaked with gasoline and the fourth was unclean. When i crank the engine with no sparks i put tissue on the top of each hole in the injector and the 3 that were drenched in gazoline leap out, however the 4th stays shut. I checked the ground connection on ECU pins 14/55,30/55 and 48/55 i get zero Ohm. Therefore, i think the issue is elsewhere.

I also tried to reset the here PID but without success. The car is able to start when the G28 is disconnected and it runs perfectly 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 value of -49c even when i unplug it. I also noticed that the oil gauge in the cockpit shows 2 bar when the actual pressure is zero.

I don't know what to do. I believe that I've eliminated 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 website pump in the g28 gets a signal from the RPM sensor. The GM-style transmitter is similar to the G4 sender and works on the 80,100,200, UrS, and RS2 vehicles. You can easily locate the spare in a salvage shop or a parts store. It is easy to test them spare audi key cost - just put your DMM into resistance mode and measure 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) engines needs to know both 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 either of these go badly, you will see codes on the audi a4 car key replacement diagnostic scanner that can cause the engine to shut down.

The signs of a failed G28 sensor include an inaccurate rev counter for the gearbox, gears shifting quicker than normal and/or misfiring when in gear. If you are experiencing any of these issues it is likely that your sensor is deteriorating and requires replacement. They're inexpensive and easy to locate especially in the case of an Bosch model like ours. If you prefer, GM's version of this component is an option.

5. Tachometer

A malfunctioning engine sensor can cause a variety of issues in your car. It is an important part of the transmission of your Audi since it sends information to the ECU about how fast or slowly the car's engine is turning. If website this sensor fails, it can disrupt the performance of the transmission, as well as the rest of the car's components.

The G5 engine speed sensor is located on the outside of the transmission, above the flywheel ring gear and sends a signal directly to the ECU at pin T55/49 through a grey wire. The ECU utilizes this signal to control the flow of fuel and boost as well as timig. It also transmits it to the G5 Tachometer located in 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 to pin T6a/1 (trace [79trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. You should detect a resistance of approximately 1000 ohms between these two points. This is a common feature across the Audi 80-100-200-RS2 series, starting from the 1985 MC all the way up to the 1997 UrS An and 1995 RS2 DU, so you might find good ones in wrecking yards.