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

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

1. Engine Speed Sensor

The grey wire is located on the edge of transmission, above the flywheel ring. The sensor sends signals through the grey wire to pin T55/49. The ECU uses this information to regulate the amount of fuel 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 has to know when the crankshaft has reached TDC, and where the camshaft lies so that it can activate the spark and injectors.

If this sensor fails, 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 jump in the chain link of the upper timing chain. However the code will not appear on its own without additional information from other sensors (G4 and G40).

It's a bit tricky to test as there are various pins on the connector and they all have different functions. The best method for doing this is to measure the resistance between the ECU and the sensor. When the sensor is fully functional, it should read approximately 1000 ohms. Examine for signs of coolant, or audi key replacement near me (redirected here) oil in the connector bay if there are problems with this part.

2. Injectors

Yesterday, when accelerating from highway paytoll at maximum speed, i noticed a huge decrease in power. It was as if 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 fourth was dry. I placed a tissue over each injector hole, and when i start the engine with no sparks, the ones with gazoline jump right out. The 4th one remains closed. I tested the ground connection of ECU pins 14,30, and 48/55. I found 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 disconnected, but it is running fine with the G28 connected. However, the intermittent misfire problem still occurs at higher RPM. The coolant sensor (G62), even when unplugged, still shows an ice temperature of -49c. I also noticed that the oil gauge in the cockpit shows 2 bars but the actual pressure is 0.

I don't know what to do. I believe that I've eliminated everything else. However, i'm afraid that I might have missed something. If anyone has suggestions, please chime in! TIA!

3. Fuel Pump

The fuel pump of the g28 receives signals from the RPM sensor. The GM-style sensor is the same as the G4 and they both work 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 to do - just put your DMM in resistance mode and measure between pins 1 (with the bump on the connector's end up) and 2 (2nd from left on the black connector's side). They must 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 about fuel injector timing etc. To do this, it uses a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these go badly, you will see codes on the diagnostic scanner that could cause engine shut down.

Some of the symptoms of a malfunctioning G28 sensor include an inaccurate gearbox rev counter and gears that shift faster than normal, and/or a misfire when in gear. If you experience any of these issues, it is likely your sensor is deteriorating and needs replacing. The good news is that they are quite affordable and readily available, especially when you're looking at the Bosch sensor, which is what ours are. You can also choose the GM version of this component is also a good choice.

5. Tachometer

A malfunctioning engine sensor can cause a myriad of issues in your car. It is a crucial part of your replacement audi key's transmission, as it sends information to the ECU about how fast or slow the car's crankshaft is spinning. This sensor could cause the transmission to fail and other components in the car to be affected.

The G5 engine speed sensor is situated on the edge of the transmission, above the flywheel ring gear. It sends a signal directly to the ECU at pin T55/49 via an uncolored wire. The ECU then processes this signal to regulate fuel, timig and boost as well as transmitting it to the G5 tachometer in the instrument cluster. You can determine if the sensor is in failure by examining the continuity from 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 [79]), and between pin T6a/1 as well as pin T26a/12. You should see approximately 1000 ohms resistance between those two pins. This is a standard part that is found across the audi Replacement key fob 80 100, 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU so good ones could be available in wrecking yards.