The No. 1 Question Anyone Working In Audi G28 Should Know How To Answer
The No. 1 Question Anyone Working In Audi G28 Should Know How To Answer
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How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician shows you how to replace the G28 Engine Speed Sensor. The sensor is located near the edges of the transmission just above the flywheel ring gear. It transmits a signal the ECU via an uncolored wire (T55/49) which is then sent to the tachometer within the instrument cluster.
1. Engine Speed Sensor
The grey wire is located on the edge of transmission, directly above the flywheel ring. The sensor transmits a signal via the grey wire to pin T55/49. The ECU uses this information to regulate the amount of fuel and boost. It also sends an indication to the G5 Tachometer in instrument cluster.
The sensor is used to correlate with the G40 Camshaft position Sensor. The ecu must know when the crankshaft has reached TDC, and the position of the camshaft, in order to activate the spark and injectors.
If this sensor fails the ECU will throw a P00160 code which means the Crank Shaft and Intake Camshaft aren't in sync, possibly indicating the chain stretching or a jump link on the upper timing chain. However, the error code won't appear on its own without additional information from other sensors (G4 and G40).
Testing is a bit challenging as there are two different connector pins, and they perform different functions but the best method of testing it is by measuring resistance between the sensor and the ECU. When the sensor is fully operational, it should be reading around 1000 ohms. If you're having issues with this sensor, look for signs of coolant or oil in the connector bay.
2. Injectors
Yesterday, when accelerating from highway paytoll at full speed, i noticed a huge decrease in power. It was as if the engine was running out of gas. Or my injectors were not firing. This morning i pull out the spark plugs, three were soaked with gazoline and the fourth was dry. When I start the engine without sparks i put tissue on the top of each hole in the injector and the 3 that were drenched in gazoline leap out, however the 4th stays shut. I tried to test the ground connections of ECU pins 14,30 and 48/55. I got 0ohm. So i assume the problem is somewhere else.
I also tried to reset PID but without success. The car will start when the G28 is disconnected and runs fine when it is plugged in, but still has the intermittent misfire issue at higher RPM. The coolant sensor (G62), even if it is not plugged more info in, shows temperatures of -49c. I also noticed that the gauge for oil pressure in the cockpit shows 2 bar while the actual pressure is 0.0 if i crank up the engine.
I'm not sure what read more to do. I think I've eliminated everything else. I'm worried that i might have missed something. If anyone has any ideas please let me know! TIA!
3. Fuel Pump
The fuel pump in the g28 receives a get more info signal from the RPM sensor. The GM-style sensor is identical to the G4 and both function in the 80, 100 200, UrS and RS2 cars so you can easily find one at a salvage yard or from a parts store. It is easy to test them: simply switch your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump at the connector's end facing upwards). They must be infinite Ohms.
4. ECU
Our 20vt turbo (3B AAN, ABY, and ADU) engines are equipped with an ECU that needs to know the speed and position of the crankshaft in order to make decisions regarding timing of the fuel injector, for example. In order to do this it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you are experiencing issues with either of these sensors, the diagnostic scanner will show codes that could lead to an engine audi spare keys shutdown.
A failing G28 sensor could cause an inaccurate speed counter for the gearbox and a gearbox which shifts faster than normal, or a misfire in the gear. If you have any of these issues, it is likely that your sensor is failing and needs replacing. The good thing is that they are very affordable and easy to find particularly in the case of the Bosch model, which is what ours are. Alternatively, the GM version of this unit is also a good option.
5. Tachometer
A malfunctioning engine sensor can cause a variety of issues in your car. It's an essential component of the transmission in your Audi, as it transmits information to the ECU regarding how fast or slow the car's engine is spinning. This sensor could cause the transmission to fail and other car components to be affected.
The G5 engine sensor is located near the edge of the transmission, over the flywheel ring. It transmits an electrical signal through a gray wire to the ECU pin T55/49. The ECU uses this signal to regulate fuel and boost, and also to timigrate. It also sends it to the G5 Tachometer inside the instrument cluster. You can test for sensor failure by examining the continuity of 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 and pin T26a/12. You should observe approximately 1000 ohms resistance between those two pins. This is a common component across the Audi 80 100, 200, UrS and RS2 range read more from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU, so the best ones might be availble in wrecking yards.