Its History Of Audi G28

How to Replace an Audi Remote key G28 Engine Speed Sensor

Charles the Humble Technician teaches 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 signal to the ECU via a grey wire (T55/49) and then to the tachometer located in the instrument cluster.

1. Engine Speed Sensor

The grey wire is located on the edge of transmission, just above the flywheel ring. The sensor transmits an electrical signal through the grey wire to pin T55/49. The ECU then uses this information to control fuel, timig and boost. It also sends an alert 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 know 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 when it fails, the ECU will display an error code P00160. This means that the Crank Shaft is not in sync with the Intake Camshaft. It could also be a sign of an issue with the chain or a jumped chain link in the upper timing chain. However the code will not appear on its own, without additional information from other sensors (G4 and G40).

It can be a bit difficult to test since there are several connector pins, and each one has 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 when the sensor is at full operation. Check for signs of coolant or oil in the connector bay if you have issues with this component.

2. Injectors

Yesterday, as i was accelerating off the highway paytoll at full speed, i noticed a huge drop in power. It was like the engine was running out of gas. Or, my injectors were not firing. I took out the spark plugs this morning and found that 3 were drenched in gasoline and the 4th was dry. I put a piece of tissue over each injector hole, and when i start the engine with no sparks, the ones that have gazoline pop right out. The fourth one remains shut. I tested the ground connection on ECU pins 14/55,30/55 and 48/55 i get 0ohm. I'm assuming that 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 works fine when the G28 connected. However the intermittent misfire issue continues to occur at higher RPM. The coolant temperature sensor (G62) shows the wrong temperature of that is -49c even after unplugging it. I also noticed that the oil gauge in the cockpit shows 2 bars while the actual pressure is 0.

I don't know what to do. I feel like i've pretty much all other possibilities out. I'm concerned that i may have missed something. Please let me know If you have any suggestions! TIA!

3. Fuel Pump

The fuel pump in the g28 can be activated by a signal sent 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 so you can easily find one at a junkyard or in a local parts store. Test them out to do - just put your DMM in resistance mode and take measurements between pins 1 (with the bump on the connector's end up) and 2 (2nd from the left on the black end of the connector). They must be infinite ohms.

4. ECU

Our 20vt turbo (3B, AAN, ABY and ADU) engines have an ECU that needs to know the speed and position of the crankshaft in order to make a decision about timing of the fuel injectors, etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these go wrong, you will receive codes on the diagnostic scanner which could cause engine shut down.

The signs of a failing G28 sensor are an inaccurate rev counter for the gearbox, gears shifting quicker than normal, and/or a misfire when you are in gear. If you are experiencing any of these issues, it is likely your sensor is failing and should be replaced. They are cheap and easy-to-find especially in the case of an Bosch sensor like ours. Alternatively, the GM version of this unit is also a good option.

5. Tachometer

A failing engine sensor could cause a variety of issues in your vehicle. It's a vital component of the audi key fobs's transmission as it sends information to the ECU about how fast or slow the vehicle's crankshaft is turning. When this sensor fails, it can affect the performance of the transmission and the other car's components.

The G5 engine sensor is located at the outskirts of transmission, above the flywheel ring. It sends signals via gray wire to ECU pin T55/49. The ECU utilizes this signal to control fuel and boost, and also to timigrate. It also transmits it to the G5 Tachometer in instrument cluster. You can check for audi a4 replacement key (autolocksmiths04400.jts-blog.com) sensor failure by examining the continuity of the sensor to the tachometer. You can also examine the continuity between pins T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]) and between pin T6a/1 as well as pin T26a/12. You should see a resistance of approximately 1000 ohms between these two points. This is a standard component across the audi spare key replacement 80 100, 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU so good ones might be availble in wrecking yards.