New And Innovative Concepts Happening With Audi G28
How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician teaches how to replace the G28 Engine Speed Sensor. The sensor is located near the edges of the transmission above the flywheel ring gear. It transmits a signal to the ECU via a grey wire (T55/49) and then to the tachometer within the instrument cluster.
1. Engine Speed Sensor
Located on the edge of the transmission above the flywheel ring gear G28 Engine Speed Sensor sends signals to ECU pin T55/49 through the grey wire. The ECU uses this information to regulate boost and fuel. It also sends an indication to the G5 tachometer inside the instrument cluster.
The sensor is used as a reference to correlate with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft is TDC and where the camshaft is located so that it can trigger spark and injectors in the right way.
If this sensor fails to function, the ECU will display a P00160 error code. This indicates that the Crank Shaft is not in alignment 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. However, the code won't be displayed on its own without additional information from other sensors (G4 and G40).
Testing is a bit tricky since there are two connector pins, and they have different functions but the most effective way to test it is to measure resistance between the sensor and the ECU. It should read about 1000 ohms when the sensor is at full operation. If you are having problems with this sensor, look for evidence of oil or coolant in the connector bay.
2. Injectors
Yesterday, while accelerating from the highway paytoll at maximum speed, i noticed a huge decrease in power. It was like the engine had run out of gas. Or, replace audi key weren't firing. I took out the spark plugs this morning, three were soaked with gasoline and the 4th was dry. I put tissue over each injector hole, and when I start the engine with no sparks, the 3 that have gazoline pop right out. The fourth one remains shut. I checked the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I get zero ohm. So i assume the problem is in another place.
I also tried to reset the PID but without success. The car is able to start when the G28 is disconnected and is running fine when it is connected however it has intermittent misfire issues at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature value of -49c even when i unplug it. Also, i noticed that the gauge for oil pressure in the cockpit shows 2 bar, whereas the actual pressure is 0.0 when I crank up the engine.
I'm not certain what to do, i believe that i've eliminated everything else. I'm concerned that i may have missed something. Let me know If you have any suggestions! TIA!
3. Fuel Pump
The fuel pump in the g28 is activated by a signal sent from the RPM sensor. The GM-style transmitter functions similarly to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. You can easily find a spare in a wrecking shop or parts store. It is easy to test them - just put 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 should 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 a decision about timing of the fuel injector, for example. To accomplish this, it uses a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you have a problem with either one of these, the diagnostic scanner will show codes that could cause an engine shutdown.
A damaged G28 sensor can cause an inaccurate gearbox speed counter, a gearbox that shifts faster than normal, or a misfire while in gear. It is likely that your sensor is failing and requires to be replaced if you encounter any of these symptoms. They're inexpensive and easy to locate, especially in the case of a Bosch sensor like ours. Alternatively, GM's version of this component is a good option.
5. Tachometer
A malfunctioning engine speed sensor could be a cause for many issues in your car. It's a crucial component of the transmission in your Audi, as it transmits information to the ECU about how fast or slow the engine of the car is turning. This sensor can cause the transmission to fail and other car components to be affected.
The G5 engine speed sensor is located on the edge of the transmission just above the flywheel ring gear. It transmits a signal to the ECU at pin T55/49, via an uncolored wire. The ECU uses this signal to control the flow of fuel and boost and also to timigrate. It also relays it to the G5 Tachometer inside the instrument cluster. You can check for sensor failure by checking continuity from the sensor to the tachometer. You can also examine the continuity between pins T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]), and between pin T6a/1 and pin T26a/12. You should see approximately 1000 ohms resistance between those points. This is the same across the Audi 80-100-200-RS2 range, from the 1985 MC up to the 1997 UrS An and 1995 RS2 Du You may also find them in wrecking yards.