How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician shows you how to replace the G28 Engine Speed Sensor. This sensor is located near the edges of the transmission just above the flywheel ring gear. It sends a message to the ECU via a grey wire T55/49, then to the tachometer in the instrument cluster.
1. Engine Speed Sensor
The grey wire is situated on the edge of transmission, just above the flywheel ring. The sensor sends a signal via the grey wire to pin T55/49. The ECU uses this information to regulate boost and fuel. It also sends a signal to the G5 tachometer in the instrument cluster.
The sensor serves as a reference for comparing with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft has reached TDC, and the location of the camshaft in order to activate the spark and injectors.
If this sensor fails, the ECU will display a P00160 error code. This means that the Crank Shaft is out of sync with the Intake Camshaft. It could also indicate a chain stretch or a jumped chain link in 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 serve different purposes however the best method to test it is to measure the resistance between the sensor and the ECU. It should read approximately 1000 ohms if the sensor is in full operation. Check for signs of coolant, or oil in the connector bay if you are experiencing problems with this part.
2. Injectors
Yesterday, as i was accelerating off the highway paytoll at full speed I noticed a significant drop in power. It was as if the engine had run out of gas. Or, my injectors were not firing. I took out the spark plugs this morning and found that 3 were soaked in gasoline, and the fourth was unclean. I put a piece of tissue over each injector hole and when I turn the engine on without sparks, the three that have gazoline pop right out. The 4th one stays closed. I tested the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ i get zero ohm. I assume that the problem is elsewhere.
I also tried to reset the PID without success. The car is able to more info start if the website G28 is not plugged in and it runs perfectly when it is connected but it still has the intermittent misfire issue at higher RPM. The coolant sensor (G62) even if it is not plugged in, shows an ice temperature of -49c. Also i noticed that the oil pressure gauge in the cockpit shows click here 2 bar, whereas the actual pressure is 0.0 if i crank up the engine.
I'm not sure what to do. I believe that I've ruled everything else out. I'm worried that i might have missed something. Please let me know If you have any suggestions! TIA!
3. Fuel Pump
The fuel pump in the g28 gets a signal from the RPM sensor. The GM-style transmitter functions similarly to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. You can easily find the spare in a salvage shop or parts store. Testing them is easy - put your DMM in resistance mode and measure between pins 1 (with the bump on the connector's side up) and 2 (2nd from left on the black end of the connector). They must be infinite ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY ADU) engines requires to know both the position and speed of the crankshaft in order to make a decision about fuel injector timing, etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you have a problem with either one of these, the diagnostic scanner will display codes that could lead to the engine shutting down.
Some of the symptoms of a malfunctioning G28 sensor include an inaccurate rev counter in the gearbox and gears that shift faster than normal and/or misfiring when you're in gear. If you experience any of these problems, it is most likely that your sensor is going bad and should be replaced. They're inexpensive and easy to locate especially when they're an Bosch sensor like ours. If you prefer, GM's version of this part would be a good option.
5. Tachometer
A failing engine speed sensor could be the cause of numerous issues with your car. It is a crucial part of your Audi's transmission, because it communicates to the ECU about how fast or slow the car's crankshaft is turning. 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 pin T55/49. The ECU is then able to process this signal to regulate fuel, timig and boost and click here then sends it on to the G5 tachometer inside the instrument cluster. You can test the sensor for failure by examining the continuity between it and the tachometer, between ECU pin T55/49 and the instrument cluster connection on pin T6a/1 (trace [79trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. There should be a resistance of approximately 1000 ohms between these two points. This is a typical part that is found across the Audi 80, 100, 200, UrS and RS2 range from 1985 MC to check here the 1997 UrS AAN and 1995 RS2 ADU. Good ones could be available in wrecking yards.