How to Replace an Audi G28 Engine Speed Sensor
In this video, Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. The sensor is located on the outside of the transmission just 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 G28 Engine Speed Sensor sends a signal to ECU pin T55/49 using an uncolored wire. 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 to link 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, to trigger the spark and injectors.
If this sensor fails when it fails, the ECU will display a P00160 error code. This indicates that the Crank Shaft is out of line with the Intake Camshaft. It could also indicate an issue with the chain or a jumpy chain link in the upper timing chain. The code won't appear without the additional information supplied by other sensors (G4 or G40).
It's a bit tricky to test as there are various connector pins, and they all have different functions. The most effective method to test it is to measure the resistance between the ECU and the sensor. It should read about 1000 ohms when the sensor is operating at its maximum. Look for evidence of coolant or oil in the connector bay if there are issues with this part.
2. Injectors
Yesterday, while accelerating from the highway paytoll at maximum speed, i noticed a huge drop in power. It was like the engine had run out of gas. Or my injectors were not firing. I pulled out the spark plugs this morning, 3 were drenched in gasoline and the 4th 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 leap out, however the 4th stays shut. I checked the ground connection of ECU pins 14,30, and 48/55. I got zero ohm. Therefore, i think the issue is elsewhere.
I also tried to reset the PID with no success. The car can start if the G28 is disconnected and it runs perfectly when it is plugged in but it still is experiencing intermittent misfires at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature value of -49c even when i unplug it. I also noticed that the oil gauge in the cockpit shows 2 bar while the actual pressure is 0.
I'm not certain what to do, i believe that i've eliminated everything else. I'm worried that i might have missed something. Please let me know If you have any suggestions! TIA!
3. Fuel Pump
The fuel pump in the g28 is activated by a signal by the RPM sensor. The GM-style transmitter functions similarly to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. It is audi lost key easy to find the spare in a salvage shop or parts store. Test them out - put 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 the left on the black end of the connector). They must be infinite ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY ADU) engines must be aware of the position and speed of the crankshaft to determine fuel injector timing, etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you have a problem with either of these, the diagnostic scanner will display codes that could cause the engine shutting down.
Some of the signs of a failed G28 sensor are an inaccurate rev counter for the gearbox the gears are shifting faster than normal, and/or a misfire when you are in gear. If you are experiencing any of these issues, it is most likely that your sensor is failing and requires replacement. The good thing is that they are quite affordable and easily accessible, especially if you're looking at the Bosch model, which is what we audi lost key have. Alternatively, the GM version of this part is also a good option.
5. Tachometer
A malfunctioning engine speed sensor could be the cause of many issues with your vehicle. It is a crucial part of the Audi's transmission because it communicates to the ECU about how fast or slow the car's crankshaft is rotating. If this sensor fails, it will affect the performance of the transmission and the other car's replacement car key audi components.
The G5 engine speed sensor is located at the edge of the transmission just above the flywheel ring gear and sends a signal directly to the ECU at pin T55/49 via an uncolored wire. The ECU is then able to process this signal to control the flow of fuel, timig and boost and then sends it on to the G5 tachometer inside the instrument cluster. You can determine if the sensor is in failure by audi car key examining the continuity from the sensor to the tachometer. Also, you can verify continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]) and between pin T6a/1 as well as pin T26a/12. You should see approximately 1000 ohms resistance between these two points. This is a standard part that is found across the Audi 80 100 200, UrS and RS2 range from 1985 MC until audi a3 key replacement near me the 1997 UrS AAN and 1995 RS2 ADU. Good ones could be available in wrecking yards.