Why Nobody Cares About Audi G28
Why Nobody Cares About Audi G28
Blog Article
How to Replace an Audi G28 Engine Speed Sensor
In this video Charles the Humble Mechanic demonstrates how to replace the G28 engine speed sensor. This sensor is located at the top of the transmission just above the flywheel ring gear. It transmits a signal the ECU via a grey wire (T55/49) and then to the tachometer located in the instrument cluster.
1. Engine Speed Sensor
The grey wire is situated on the outside of the transmission, above the flywheel ring. This sensor sends an electrical signal through the grey wire to pin T55/49. The ECU uses this information to regulate fuel and boost. It also sends signals to the G5 tachometer inside the instrument cluster.
The sensor is used to correlate with the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft is TDC and where the camshaft is so it can start spark and injectors according to the situation.
If this sensor fails the ECU will show a P00160 code which means the Crank Shaft and Intake Camshaft aren't in sync, possibly indicating chain stretch or a jumped link on the upper timing chain. The code will not appear without the additional information provided by other sensors (G4 or G40).
Testing is a bit challenging since there are two connector pins, and they have different functions but the most effective method of testing it is to measure resistance between the sensor and the ECU. When the sensor is operational, it should be reading approximately 1000 ohms. Check for signs of coolant, or oil in the connector bay if you have issues with this component.
2. Injectors
Yesterday, while accelerating from the highway paytoll at maximum speed, i noticed a huge drop in power. It was as if the engine had run out of gas. Or my injectors weren't firing. Today, i pulled out the spark plugs, 3 were soaked with gazoline and the fourth was dry. I put tissue over each injector hole and when i turn the engine on without sparks, the ones with gazoline jump out. The 4th one stays shut. I tried to test the ground connections 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 but with no luck. The car read more will start when the G28 is unplugged, and it works fine when the G28 connected. However the intermittent misfire issue persists at higher RPM. The coolant sensor (G62), even if it is not plugged in, shows temperatures of -49c. Also, i noticed that the gauge for oil pressure in the cockpit is showing 2 bar, whereas the actual pressure is 0.0 if i crank up the engine.
I'm not sure what to do, as i think i've pretty much ruled out everything else. But i am afraid i might have missed something. If anyone has any suggestions, please share them! TIA!
3. Fuel Pump
The fuel pump in the g28 can be activated by a signal sent by 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 find a spare in a wrecking shop or a parts store. It is easy to test them - just switch your DMM into resistance mode and test the distance between pins 1 and 2 (with the bump at the connector's end facing upwards). They must be infinite Ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY) engines must know the position and speed the crankshaft in order to make a decision about fuel injector timing, etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you encounter a problem with either of these, the diagnostic scanner will show codes that could cause an engine shutdown.
A failing G28 sensor could result in an inaccurate gearbox speed counter or a gearbox that shifts more quickly than normal, and/or a misfire in gear. It is possible that the sensor is failing and needs to be replaced if you encounter any of these symptoms. They're inexpensive more info and easy click here to locate especially if they're a Bosch model like ours. Alternatively, the GM version of this part is also a great option.
5. Tachometer
A faulty engine speed sensor could be the cause of numerous issues with your car. It's an essential component of your Audi's transmission, since it relays information to the ECU about how the car's crankshaft is rotating. 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 sends an electrical signal through an uncolored wire to the ECU get more info pin T55/49. The ECU is then able to process this signal to control fuel, timig and boost and then transmitting it to the G5 tachometer inside the instrument cluster. You can test the sensor for failure by checking continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection on pin T6a/1 (trace [79trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. You should observe approximately 1000 ohms of resistance between those two pins. This part read more is common across the Audi 80-100-200-RS2 model, ranging from the 1985 MC all the way up to the 1997 UrS AN and 1995 RS2 Du You may also find good ones in wrecking yards.