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 at the top of the transmission just above the flywheel ring gear. It sends a signal to the ECU via a grey wire (T55/49) and then to the tachometer in the instrument cluster.
1. Engine Speed Sensor
Located on the edge of the transmission, above the flywheel ring gear the G28 Engine Speed Sensor sends an electrical signal to ECU pin T55/49 through an uncolored wire. The ECU then utilizes this information to regulate the flow of fuel, timig and boost. It also sends an indication to the G5 Tachometer in instrument cluster.
The sensor is used to connect the G40 Camshaft position Sensor. The ecu has to be aware of when the crankshaft has reached TDC, and the position of the camshaft, so that it can activate the spark and injectors.
If this sensor fails, the ECU will display a P00160 error message. This means that the Crank Shaft is not in sync with the Intake Camshaft. It could also be a sign of the possibility of a chain stretch or jumpy chain link in the upper chain of timing. However, the error code won't appear on its own, without additional information from other sensors (G4 and G40).
Testing is a bit tricky because there are two pins for the connector and they perform different functions but the most effective method to test it is to measure resistance between the sensor and the ECU. It should read about 1000 ohms when the sensor is operating at its maximum. If you're experiencing issues with this part, check for signs of coolant or oil in the connector bay.
2. Injectors
Yesterday accelerating full speed from highway paytoll, i experienced massive power loss like the engine is running out of gas or injectors are not firing anymore. I took out the spark plugs this morning and found that 3 were soaked with gasoline and the fourth was unclean. I put tissue over each injector hole, and when I start the engine with no sparks, the ones that have gazoline pop right out. The fourth one remains shut. I tested the ground connection on ECU pins 14/55, 30/55 and 48/55. I get 0ohm. Therefore, i think the issue is elsewhere.
I also tried to reset the PID with no success. The car will start when the G28 is unplugged, and it is running fine with the G28 connected. However the intermittent misfire issue continues to occur at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temp value that is -49c even after unplugging it. I also noticed that the oil gauge in the cockpit shows 2 bars when the actual pressure is 0.
I'm not sure what to do, as i feel i have pretty much completely ruled out all other possibilities. But i'm worried that I might have missed something. If anyone has any suggestions, please chime in! TIA!
3. Fuel Pump
The fuel pump in the g28 receives signals 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 junkyard or at a parts store. It is easy to test them - just 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 must know the position and speed of the crankshaft to make decisions regarding fuel injector timing etc. To accomplish this, it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you are experiencing issues with either one of these, the diagnostic scanner will display codes that could cause the engine shutting down.
A damaged G28 sensor could cause an inaccurate speed counter for the gearbox or a gearbox that shifts faster than normal, and/or a misfire while in gear. It is possible that your sensor is more info failing and requires to be replaced if you experience any of these symptoms. They are cheap and easy-to-find, especially in the case of an Bosch sensor like ours. Alternately, the GM version of this part is also a good choice.
5. Tachometer
A faulty engine speed sensor could be the reason behind numerous issues in your car. It's an essential component of the Audi's transmission because it communicates to the ECU about how fast or slow the car's crankshaft is rotating. This sensor could cause the transmission to malfunction website and other components in the car to be affected.
The G5 engine sensor is located at the edge of the transmission, over the flywheel ring. It sends signals via a gray wire to the ECU pin T55/49. The ECU utilizes this signal to control the flow of fuel and boost as well as timig. It also transmits it to the G5 Tachometer inside the instrument cluster. You can determine if the sensor check here is in failure by examining the continuity from the sensor to the tachometer. Also, you get more info 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 as well as pin T26a/12. You should observe approximately 1000 ohms resistance between these two points. This is the same across the Audi 80-100-200-RS2 model, ranging from the 1985 MC up to click here the 1997 UrS AN and 1995 RS2 Du, so you might find good ones in wrecking yards.