Why No One Cares About Audi G28

How to Replace an audi spare key cost G28 Engine Speed Sensor

In this video Charles the Humble Mechanic demonstrates how to replace the G28 engine speed sensor. This sensor is located on the edge of the transmission above the flywheel ring gear. It sends a message to the ECU through a grey wire T55/49, then to the tachometer on the instrument cluster.

1. Engine Speed Sensor

It is located on the outside of the transmission, above the flywheel ring gear the G28 Engine Speed Sensor sends a signal to ECU pin T55/49 using an uncolored wire. The ECU utilizes this information to control fuel and boost. It also sends an alert to the G5 Tachometer in instrument cluster.

The sensor is used to correlate with the G40 Camshaft position Sensor. The ecu has to be aware of when the crankshaft has reached TDC, and the position of the camshaft, so that it can activate the spark and injectors.

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

Testing can be a bit difficult as there are two different connector pins and they perform different functions but the most effective method of testing it is to measure resistance between the sensor and the ECU. It should read around 1000 ohms when it is at full operation. Examine for signs of coolant or oil in the connector bay if you are experiencing problems with this part.

2. Injectors

Yesterday, when accelerating from highway paytoll at maximum speed I noticed a significant drop in power. It was like the engine was running out of gas. Or my injectors weren't firing. I pulled out the spark plugs this morning and found that 3 were soaked in gasoline, and the fourth was dry. When i crank the engine without sparks, I put a piece of tissue on top of each injector hole and the 3 drenched with gazoline leap out, however the 4th one stays closed. I inspected the ground connection on ECU pins 14/55, 30/55 and 48/55. i get zero Ohm. I'm assuming the issue is somewhere else.

I also tried to reset the PID but with no luck. The car will start when the G28 is unplugged, Audi Key programmer and it is running fine with the G28 connected. However the intermittent misfire issue continues to occur at higher RPM. The coolant sensor (G62), even if it is not plugged in, shows an ice temperature of -49c. I also noticed that the oil gauge in the cockpit shows 2 bar but the actual pressure is zero.

I'm not sure what to do, but i feel i have pretty much completely ruled out all other possibilities. I'm afraid i may have missed something. If anyone has any ideas please chime in! TIA!

3. Fuel Pump

The fuel pump in the g28 can be activated by a signal by the RPM sensor. The GM-style transmitter is identical to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. You can easily locate the spare in a salvage shop or parts store. Testing them is easy - put your DMM in resistance mode and take measurements between pins 1 (with the bump on the connector's side up) and 2 (2nd from left on the black connector's end). They should be infinite ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY, and ADU) engines are equipped with an ECU that must know the position and speed of the crankshaft to make decisions regarding timing of the fuel injector, for example. To accomplish this, it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these goes bad you will get codes on the diagnostic scanner that could cause engine shut down.

A failing G28 sensor could result in an inaccurate gearbox speed counter and a gearbox which shifts more quickly than normal, or a misfire in the gear. If you are experiencing any of these problems, it is most likely that your sensor is deteriorating and requires replacement. The good thing is that they are very cheap and readily available particularly when you're looking at a Bosch sensor, which is what we have. Alternatively, GM's version of this part would be a good option.

5. Tachometer

A damaged engine sensor could cause a variety of issues in your vehicle. It's a vital component of your Audi Replacement Key Cost's transmission, as it sends information to the ECU about how the car's crankshaft is turning. This sensor could cause the transmission to fail and other audi car key replacement components to be affected.

The G5 engine sensor is located near the edge of the transmission, over the flywheel ring. It transmits an electrical signal through a gray wire to the ECU pin T55/49. The ECU utilizes this signal to control the amount of fuel and boost, and also timig. It also transmits 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 via pin T6a/1 (trace [79trace [79]) and key for Audi between pin T6a/1 and the instrument cluster pin T26a/12. You should observe around 1000 ohms of resistance between these two points. This is a standard part across the audi replacement key service 80 100, 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU. Good ones could be available in wrecking yards.