Why No One Cares About Audi G28
How to Replace an Audi G28 Engine Speed SensorCharles the Humble Technician shows how to replace the G28 Engine Speed Sensor. The sensor is situated at the top of the transmission just above the flywheel ring gear. It sends a signal to the ECU via the grey wire (T55/49) and then to the tachometer located in the instrument cluster.
1. Engine Speed Sensor
The grey wire is located on the edge of transmission, just above the flywheel ring. The sensor sends signals through the grey wire to pin T55/49. The ECU then utilizes this information to regulate fuel, timig and boost. It also sends a signal to the G5 Tachometer located in the instrument cluster.
The sensor is used to link the G40 Camshaft position Sensor. The ecu has to know when the crankshaft reached TDC and also the location of the camshaft so that it can activate the spark and injectors.
If this sensor fails to function, the ECU will display a P00160 error code. This indicates that the Crank Shaft is not in line with the Intake Camshaft. It could also indicate a chain stretch or a jumped chain link in the upper chain of timing. However, the error code won't be displayed on its own without additional information from other sensors (G4 and G40).
Testing is a bit tricky as there are two different connector pins, and they serve different purposes but the most effective way to test it is by measuring resistance between the sensor and the ECU. It should read about 1000 ohms when the sensor is operating at its maximum. If you're having issues with this part, check for evidence of coolant or oil in the connector bay.
2. Injectors
Yesterday, when accelerating from highway paytoll at maximum speed, i noticed a huge drop in power. It was like the engine was running out of gas. Or my injectors weren't firing. I took out the spark plugs this morning, three were drenched in gasoline and the fourth was unclean. When i crank the engine without sparks i put tissue on the top of each hole in the injector, 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 0ohm. I think the issue is elsewhere.
I also tried to reset the PID with no success. The car will start when the G28 is disconnected, but it runs fine with the G28 connected. However the intermittent misfire issue persists at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature value of -49c, even if I unplug it. I get more info also noticed that the oil gauge in the cockpit shows 2 bars while the actual pressure is zero.
I don't know what to do. I feel like i've pretty much ruled everything else out. I'm concerned that i may have missed something. Please let me know should you have any suggestions! TIA!
3. Fuel Pump
The fuel pump of the g28 gets a signal from the RPM sensor. The GM-style transmitter is identical to the G4 and both function in the 80, 100 200, UrS and RS2 cars which is why you can easily locate one at a wrecking yard or in a local parts store. Test them out by putting your DMM in resistance mode and take measurements between pins 1 (with the bump on the connector's side 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 has to know the position and speed of the crankshaft to make a decision about timing of the fuel injector, for example. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you are experiencing issues with either of these sensors, the diagnostic scanner will display codes that could cause the engine shutting down.
A failing G28 sensor can cause an inaccurate gearbox speed counter, a gearbox that shifts more quickly than normal, or a misfire in the gear. It is probable that the sensor is failing and needs to be replaced if you encounter any of these symptoms. The get more info good news is they are very affordable and easily accessible, especially in the case of the Bosch unit which is what we have. Alternately, the GM version of this component is also a good option.
5. Tachometer
A malfunctioning engine speed sensor could be the cause of numerous problems in your car. It's a crucial component of the transmission in your Audi since it sends information to the ECU about how how much is a replacement audi key fast or slow the car's engine is spinning. When this sensor fails, it will disrupt the performance of the transmission, as well as the rest of the car's components.
The G5 engine sensor is located at the outskirts of the transmission, just above the flywheel ring. It sends signals via a gray wire to the ECU read more pin T55/49. The ECU then uses and processes this signal to control fuel, timig and boost, and also transmitting it to the G5 tachometer in 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 via pin T6a/1 (trace [79trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. You should see the resistance to be around 1000 ohms in these areas. This is a typical part that is more info 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.