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 on the outside of the transmission over the flywheel gear. It transmits a signal the ECU via a grey wire (T55/49) and then to the tachometer located in the instrument cluster.
1. Engine Speed Sensor
Located on the edge of the transmission above the flywheel ring gear G28 Engine Speed Sensor sends an electrical signal to ECU pin T55/49 through a grey wire. The ECU then uses this information to control fuel, timig and boost. It also sends a signal 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 needs to know when the crankshaft reached TDC and also the position of the camshaft, to trigger the spark and injectors.
If this sensor fails, the ECU will display a P00160 error code. This means that the Crank Shaft is not in line with the Intake Camshaft. It could also be a sign of an issue with the chain or a jump in the chain link of the upper chain. However the code will not be displayed on its own without additional information from other sensors (G4 and G40).
Testing is a bit challenging because there are two connector pins and they have different functions however the best way to test it is by measuring resistance between the sensor and the ECU. If the sensor is operational, it should be reading about 1000 ohms. If you're experiencing issues with this part, check for signs of coolant or oil in the connector bay.
2. Injectors
Yesterday, while accelerating at full speed from the highway paytoll, I experienced massive power loss as if the engine was running out of gas or the injectors are not firing at all. I pulled out the spark plugs this morning, three were drenched in gasoline and the 4th was dry. When i crank the engine, there are no sparks, i place a tissue on the top of each hole in the injector and the 3 drenched with gazoline leap out, however the 4th stay closed. I tried to test the ground connections of ECU pins 14,30 and 48/55. I got zero ohm. Therefore, i think the issue is somewhere else.
I also tried to reset the PID but with no luck. The car can start if the G28 is unplugged and runs fine when it is plugged in but it still has the intermittent misfire issue at higher RPM. The coolant sensor (G62), even when unplugged, still shows temperatures of -49c. Also i noticed that the oil pressure gauge in the click here cockpit shows 2 bar, whereas the actual pressure is 0.0 when i rev the engine.
I'm not certain what to do, i believe that i've eliminated everything else. However, i'm afraid that i might have missed something. If anyone has suggestions, please let me know! TIA!
3. Fuel Pump
The fuel pump in the g28 can be activated by a signal by the RPM sensor. The GM-style transmitter is identical to the G4 sender and works on the 80,100,200, UrS, and RS2 vehicles. You can easily locate the spare in a salvage shop or a parts store. Test them out to do - just put your DMM in resistance click here mode and measure between pins 1 (with the bump on the connector's side up) and here 2 (2nd from the left on the black connector's end). They must be infinite Ohms.
4. ECU
Our 20vt turbo (3B AAN, ABY, and ADU) engines are equipped with an ECU that needs to be aware of the speed and position of the crankshaft to make a decision about timing of the fuel injector, for example. To do this, it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If click here either of these go wrong, you will receive codes on the diagnostic scanner that can cause the engine to shut down.
The signs of a malfunctioning G28 sensor include an inaccurate rev counter in the gearbox and gears that shift faster than normal and/or a misfire when in gear. It is probable that your sensor click here is failing and requires to be replaced if you experience any of these symptoms. They're inexpensive and easy to locate, especially if they're a Bosch sensor like ours. Alternately, the GM version of this part is also a good choice.
5. Tachometer
A failing engine sensor could cause a variety of issues within your vehicle. It's an essential component of your Audi's transmission, as it sends information to the ECU about how the car's crankshaft is spinning. This sensor can cause the transmission to fail and other components of the car to be affected.
The G5 engine speed sensor is located at the outside of the transmission just above the flywheel ring gear. It sends a signal to the ECU at pin T55/49 via a grey wire. The ECU then uses and processes this signal to control fuel, timig and boost and then sends it on to the G5 tachometer inside the instrument cluster. You can test the sensor for any failure by checking the continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. There should be a resistance of approximately 1000 ohms between these points. This is a common feature across the Audi 80-100-200-RS2 model, ranging from the 1985 MC all the way up to the 1997 UrS AN and the 1995 RS2 Du You may also find good ones in wrecking yards.