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

Charles the Humble Technician shows you how to replace the G28 Engine Speed Sensor. The sensor is located on the outside of the transmission, above the flywheel 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

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 the grey wire. The ECU then uses this information to control fuel, timig and boost. It also sends an indication to the G5 Tachometer in instrument cluster.

The sensor is used to correlate the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft has reached TDC, and the position of the camshaft, in order to activate the spark and injectors.

If this sensor fails when it fails, the ECU will display a P00160 error message. This means that the Crank Shaft is out of line with the Intake Camshaft. It could also indicate an issue with the chain or a jump in the chain link of the upper timing chain. However the code will not be displayed on its own without additional information from other sensors (G4 and G40).

Testing is a bit challenging since there are two pins for the connector and they have different functions but the most effective way to test it is by measuring resistance between the sensor and the ECU. If the sensor is operational, it should read around 1000 ohms. If you are having problems with this part, check for evidence of oil or coolant in the connector bay.

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 injectors are not firing at all. 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 drenched with gazoline jump out but the 4th stays shut. I tested the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I get zero Ohm. I think the issue is elsewhere.

I also tried to reset the PID without success. The car can start if the G28 is not plugged in and is running fine when it is connected but it still has intermittent misfire issues at higher RPM. The coolant sensor (G62), even when unplugged, still shows temperatures of -49c. Also, i noticed that the gauge for oil pressure in the cockpit is showing 2 bar while the actual pressure is 0.0 if i crank up the engine.

I'm not certain what to do, i think i've pretty much ruled out everything else. I'm concerned that i may have missed something. Let me know if you have any ideas! TIA!

3. Fuel Pump

The fuel pump of the g28 receives signals 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 a spare in a wrecking shop or 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 left on the black connector's side). They should be infinite Ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY, and ADU) engines have an ECU that must know the speed and position of the crankshaft in order to make decisions regarding fuel injector timing etc. To do this, it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these go bad you will get codes on the diagnostic scanner that can cause the engine to shut down.

A malfunctioning G28 sensor could result in an inaccurate speed counter for your gearbox, a gearbox that shifts more quickly than normal, and/or an unfire when in the gear. If you have any of these problems, it is likely your sensor is going bad and needs replacing. The good news is that they are very affordable and easy to find, especially if you're looking at 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 variety of issues in your car. It's an essential component of the transmission of your Audi, as it transmits information to the ECU regarding how fast or slow the engine is spinning. When this sensor fails, it can disrupt the performance of the transmission and the rest of the car key replacement audi's components.

The G5 engine speed sensor is located on 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 uses this signal to regulate the amount of fuel and boost, as well as timig. It also sends it to the G5 Tachometer inside the instrument cluster. You can check the sensor for audi tt Key programming failure by examining the continuity between it and the tachometer, between ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. There should be a resistance of approximately 1000 ohms between these two points. This is a typical part that is found across the audi tt key programming [Going in Promarket In] 80 100, 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU. Good ones could be available in wrecking yards.