10 Situations When You'll Need To Be Educated About Audi G28

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

Charles the Humble Technician teaches you 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 to the ECU via an uncolored wire T55/49, then to the tachometer located on the instrument cluster.

1. Engine Speed Sensor

The grey wire is located at the edges of the transmission, just above the flywheel ring. This sensor sends signals through the grey wire to pin T55/49. The ECU then uses this information to control fuel, timig and boost. It also sends signals to the G5 Tachometer located in the instrument cluster.

The sensor is used as a reference to correlate with the G40 Camshaft Position Sensor. The ecu needs to know when the crankshaft has reached TDC and also the position of the camshaft, to trigger the spark and injectors.

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

Testing is a bit tricky because there are two connector pins, and they have different functions but the most effective method of testing it is by measuring resistance between the sensor and the ECU. It should read about 1000 ohms when the sensor is operating at its maximum. Examine for signs of coolant or oil in the connector bay if you are experiencing issues with this part.

2. Injectors

Yesterday, when i was accelerating to the fullest speed from highway paytoll, I experienced massive power loss like the engine is out of gas or the injectors are not firing anymore. In the morning, i removed the spark plugs, three were drenched with gazoline the fourth one was dry. When i crank the engine with no sparks, I put a piece of tissue on top of each injector hole, the 3 drenched with gazoline jump out but the 4th stay shut. I checked the ground connection of ECU pins 14,30, and 48/55. I got zero ohm. I think the issue is somewhere else.

I also tried to reset the PID with no success. The car is able to start when the G28 is disconnected and is running fine when it is plugged in, but still is experiencing intermittent misfires at higher RPM. The coolant temperature sensor (G62) shows the wrong temp value -49c even when i unplug it. I also noticed that the gauge for oil pressure in the cockpit is showing 2 bar when the actual pressure is 0.0 when i rev the engine.

I'm not certain what to do, but i believe that i've completely ruled out all other possibilities. I'm worried that i might have missed something. If anyone has any suggestions, please chime in! TIA!

3. Fuel Pump

The fuel pump of the g28 receives a signal from the RPM sensor. The GM-style sensor is the same as the G4 and both are used 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. Test them out by putting your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector's end up) and 2 (2nd from left on the black connector's side). They should be infinite Ohms.

4. ECU

The ECU of our 20vt turbo (3B AAN ABY) engines must know the position and speed the crankshaft in order to make a decision about timing of the fuel injector, etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If you are experiencing issues with either of these, the diagnostic scanner will display the codes that could trigger an engine shutdown.

A failing G28 sensor could result in an inaccurate speed counter for your gearbox, a gearbox that shifts more quickly than normal, or a misfire in gear. It is probable that your sensor is failing and needs to be replaced if you experience any of these symptoms. The good news is that they are quite affordable and easy to find, especially if you're looking at a Bosch unit which is what we have. Alternatively, the GM version of this unit is also a great option.

5. Tachometer

A failing engine speed sensor could be the cause of numerous problems in your vehicle. It's a crucial component of the transmission cost of audi key replacement your audi key shell because it relays information to the ECU regarding how fast or slow the car's engine is spinning. This sensor could cause the transmission to fail and other components of the car to be affected.

The G5 engine speed sensor is situated on the edge of the transmission above the flywheel ring gear and sends a signal directly to the ECU at pin T55/49 via a grey wire. The ECU uses this signal to regulate the flow of fuel and boost as well as timig. It also sends it to the G5 Tachometer located in the instrument cluster. You can determine if the sensor is in failure by examining the continuity of the sensor to the tachometer. Additionally, you can 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 and pin T26a/12. You should observe approximately 1000 ohms of resistance between those points. This is a standard part across the audi key replacement near me new audi tt key fob not working (clicking here) 80, 100 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU, so the best ones might be availble in wrecking yards.