20 Myths About Audi G28: Dispelled
20 Myths About Audi G28: Dispelled
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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. This sensor is located on the outside of the transmission just above the flywheel gear. It sends a message 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 signals to ECU pin T55/49 using an uncolored wire. The ECU then utilizes this information to regulate fuel, timig and boost. It also sends signals to the G5 tachometer in the instrument cluster.
The sensor is used to correlate the G40 Camshaft position Sensor. The ecu needs to be aware of 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 throw the P00160 error, which means the Crank Shaft and Intake Camshaft are not in sync and possibly indicating the chain is stretched or a jump link on the upper timing chain. However, the error code won't be displayed on its own without additional information from other sensors (G4 and G40).
It can be a bit difficult to test as there are different pins on the connector and they all have different functions. The most effective method to test it is to measure the resistance between the ECU and the sensor. When the sensor is fully operational, it should be reading about 1000 ohms. Examine for evidence of coolant or oil in the connector bay if you have issues with this component.
2. Injectors
Yesterday accelerating full speed from highway paytoll, i experienced massive power loss like the engine is out of gas or injectors aren't firing at all. Today, i pulled out the spark plugs. Three were drenched with gazoline the 4th one was dry. I put tissue over each injector hole and when i start the engine without sparks, the 3 that have gazoline pop right out. The 4th one stays closed. I tested the ground connection on ECU pins 14/55, 30/55 and 48/55. I got zero ohm. I think the issue is elsewhere.
I also tried to reset the PID without success. The car will start if the G28 is unplugged and is running fine when it is connected however it 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 shows 2 bar when the actual pressure is 0.0 when I crank up the engine.
I'm not sure what to do. I believe that I've all other possibilities out. I'm afraid i may have missed something. Please let me know should you have any suggestions! TIA!
3. Fuel Pump
The fuel pump on the g28 is activated by a signal audi replacement keys from the RPM sensor. The GM-style transmitter functions similarly to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. You can easily locate an extra in a wrecking shop or parts store. Test them out by putting your DMM in resistance mode and measure between pins 1 (with website 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 in our 20vt turbo (3B AAN ABY) engines must know the position and speed the crankshaft to make decisions regarding timing of the fuel injector, etc. It check here uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these goes badly, you will see codes on the diagnostic scanner which can lead to engine shutdown.
Some audi a3 replacement key of the symptoms of a malfunctioning G28 sensor are an inaccurate rev counter for the gearbox the gears are shifting faster than normal and/or misfiring when in gear. If you experience any of these problems, it is most likely that your sensor is failing and should be replaced. The good news is they are very cheap and readily available particularly when you're looking at an Bosch model, like ours. Alternatively, the GM version of this component is also a good option.
5. Tachometer
A faulty engine speed sensor could be a cause for many issues in your vehicle. It's an essential component of your Audi's transmission, since it relays information to the ECU about how fast or slow the vehicle's crankshaft is turning. If this sensor fails, it could disrupt the performance of the transmission, as well as the other car's components.
The G5 engine sensor is located at the edge of the transmission, over the flywheel ring. It transmits a signal via gray wire to ECU pin T55/49. The ECU uses this more info signal to control fuel and boost, and also timig. It also relays it to the G5 Tachometer inside 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 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. It should show approximately 1000 ohms of resistance between those points. This is a standard part that is found across the Audi 80 100 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU, so the best ones might be availble in wrecking yards.