Its History Of Audi G28

How to Replace an audi keys replacement G28 Engine Speed Sensor

Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. The sensor is situated near the edges of the transmission just above the flywheel ring gear. It transmits a signal to the ECU via an uncolored wire (T55/49), then to the tachometer within the instrument cluster.

1. Engine Speed Sensor

The sensor is located at the edge of the transmission above the flywheel ring gear, the G28 Engine Speed Sensor sends an electrical signal to ECU pin T55/49 through the grey wire. The ECU then utilizes this information to regulate the flow of fuel, timig and boost. It also sends a signal to the G5 Tachometer located in the 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 also the position of the camshaft, in order to activate the spark and injectors.

If this sensor fails the ECU will display an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are out of sync and could indicate the chain stretching or a jump link on the upper chain of timing. The code won't show without the additional information supplied by other sensors (G4 or G40).

Testing is a bit challenging because there are two connector pins and they serve different purposes but the best way to test it is to measure the resistance between the sensor and the ECU. It should read around 1000 ohms when it is operating at its maximum. If you're having issues with this part, check for signs of oil or coolant in the connector bay.

2. Injectors

Yesterday, when i was accelerating to the fullest speed from highway paytoll, I experienced a big cut in power like the engine is running out of gas or injectors aren't firing at all. I pulled out the spark plugs this morning, 3 were soaked with gasoline and the fourth was unclean. When I crank the engine, there are no sparks, i place a tissue on top of each injector hole and the 3 that were drenched in gazoline jump out but the 4th stays closed. I tried to test the ground connections of ECU pins 14,30 and 48/55. I found zero ohm. So i assume the problem is elsewhere.

I also tried to reset PID without success. The car will start when the G28 is unplugged, audi key fob replacement cost tt replacement audi q5 key (https://bookmarkleader.com/story18203804/are-you-responsible-for-an-Audi-key-programming-budget-12-top-ways-to-spend-your-money) and it is running fine with the G28 connected. However, the intermittent misfire problem still occurs at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature of -49c even when i unplug it. I also noticed that the oil gauge in the cockpit shows 2 bars but the actual pressure is 0.

I'm not sure what to do, as i believe that i've eliminated everything else. However, i'm afraid that I might have missed something. Let me know If you have any suggestions! TIA!

3. Fuel Pump

The fuel pump in the g28 is activated by a signal sent by the RPM sensor. The GM-style transmitter 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. It is simple to test them by putting your DMM in resistance mode and measure the resistance 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 have an ECU that has to know the position and speed of the crankshaft in order to make a decision about timing of the fuel injectors, etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If either of these go badly, you will see codes on the diagnostic scanner which can lead to engine shutdown.

Some of the signs of a malfunctioning G28 sensor are an inaccurate rev counter in the gearbox and gears that shift faster than normal and/or misfiring when in gear. If you experience any of these problems, it is likely that your sensor is going bad and should be replaced. The good news is they are very affordable and readily available, especially when you're looking at the Bosch unit which is what ours are. Alternatively, the GM version of this unit is also a good option.

5. Tachometer

A failing engine speed sensor could be the reason behind many problems in your vehicle. It is an important part of the transmission in your audi remote key because it relays information to the ECU on how fast or slowly the engine of the car is spinning. This sensor could cause the transmission to fail and other components in the car to be affected.

The G5 engine sensor is located at the edge of transmission, above the flywheel ring. It transmits a signal via an uncolored wire to the ECU pin T55/49. The ECU uses this signal to control the flow of fuel and boost and also timig. It also transmits it to the G5 Tachometer in instrument cluster. You can determine if the sensor is in failure by checking continuity from the sensor to the tachometer. You can also check continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]), and between pin T6a/1 and pin T26a/12. There should be an average resistance of 1000 ohms between these two points. This is a common feature across the Audi Replacement Key Cost 80-100-200-RS2 range, beginning with the 1985 MC and up to the 1997 UrS AN and the 1995 RS2 DU, so you might find some good ones in wrecking yards.