How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. The sensor is located at the top of the transmission just above the flywheel ring gear. It transmits 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, 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 boost and fuel. It also sends an alert to the G5 Tachometer located in the instrument cluster.
The sensor is used as a reference to correlate with the G40 Camshaft Position Sensor. The ecu must be aware when the crankshaft is TDC and the location of the camshaft so it can trigger spark and injectors in the right way.
If this sensor 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 be a sign of a chain stretch or a jumpy chain link in the upper chain of timing. However the code will not be displayed on its own without additional information from other sensors (G4 and G40).
Testing can be a bit difficult because there are two connector pins and they perform different functions but the best way to test it is by measuring resistance between the sensor and the ECU. It should read around 1000 ohms when the sensor is in full operation. If you're experiencing issues with this component, look for evidence of oil or coolant in the connector bay.
2. Injectors
Yesterday, when accelerating from highway paytoll at full speed I noticed a massive reduction in power. It was as if the engine had run out of gas. Or my injectors were not firing. In the morning, i removed the spark plugs. Three were drenched with gazoline the 4th one was dry. When i crank the engine with no sparks i put tissue on the top of each hole in the injector and 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 in another place.
I also tried to reset the PID but without success. The car will start when the G28 is unplugged and it runs perfectly when it is plugged in, but still has the intermittent misfire issue at higher RPM. The coolant sensor (G62), even when unplugged, still shows an ice temperature of -49c. I also noticed that the gauge for oil pressure in the cockpit is showing 2 bar while the actual pressure is 0.0 when I crank up the engine.
I'm not sure what to do. I think I've ruled everything else out. But i'm worried that I might have missed something. If anyone has suggestions, please let me know! TIA!
3. Fuel Pump
The fuel pump in the g28 receives a signal from the RPM sensor. The GM-style transmitter is identical to the G4 and both are used in the 80, 100, 200, UrS and RS2 cars so you can easily find one at a wrecking yard or from a parts store. It is simple to test them - just put your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump at the connector's end facing up). They must be infinite Ohms.
4. ECU
Our 20vt turbo (3B AAN, ABY and ADU) engines have an ECU that must know the speed and position of the crankshaft in order to make decisions regarding timing of the fuel injectors, etc. To do this, it utilizes a Crank Position Sensor (G4) audi convenience key and an Engine Speed Sensor (G28). If you encounter a problem with either of these sensors, the diagnostic scanner will show the codes that could trigger an engine shutdown.
Some of the signs of a failed G28 sensor include an inaccurate gearbox rev counter the gears are shifting faster than normal and/or a misfire when lost audi keys you are in gear. If you have any of these problems, it is most likely that your sensor is deteriorating and should be replaced. The good thing is that they are very affordable and readily available particularly in the case of the Bosch model, like ours. Alternately, the GM version of this component is also a good choice.
5. Tachometer
A faulty engine speed sensor could be the reason behind numerous issues in here your vehicle. It's a vital component of your Audi's transmission, as it sends information to the ECU about how fast or slow the vehicle's crankshaft is rotating. When this sensor fails, it can affect the performance audi a3 key replacement of the transmission, as well as the other car's components.
The G5 engine sensor is located near the edge of the transmission, just above the flywheel ring. It sends 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 timig. It also sends it to the G5 Tachometer located in the instrument cluster. You can check for sensor failure by examining the continuity of 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 and pin T26a/12. You should see an average resistance of 1000 ohms in these areas. click here This is the same across the Audi 80-100-200-RS2 model, ranging from the 1985 MC up to the 1997 UrS An and 1995 RS2 Du So, you may find good ones in wrecking yards.