How to Replace an Audi G28 Engine Speed Sensor
In this video Charles the humble mechanic demonstrates how to replace the G28 engine speed sensor. The sensor is situated at the top of the transmission above the flywheel ring gear. It transmits a signal the ECU via a grey wire (T55/49), then to the tachometer within the instrument cluster.
1. Engine Speed Sensor
The grey wire is situated at the edges of the transmission, directly above the flywheel ring. The sensor sends an electrical signal through the grey wire to pin T55/49. The ECU then uses this information to control the boost, fuel, and timig. It also sends an indication to the G5 Tachometer in instrument cluster.
The sensor is used as a reference point to connect with the G40 Camshaft Position Sensor. The ecu needs to know when the crankshaft is TDC and the location of the camshaft so it can trigger spark and injectors accordingly.
If this sensor fails, the ECU will show a P00160 code which means the Crank Shaft and Intake Camshaft are not in sync, possibly indicating the chain stretching or a jump link on the upper chain of timing. The code won't appear without the additional information supplied by other sensors (G4 or G40).
Testing is a bit challenging since there are two pins for the connector and they have different functions but the most effective method to test it is to measure the resistance between the sensor and the ECU. When the sensor is fully operational, it should read approximately 1000 ohms. Look for signs of coolant or oil in the connector bay if there are problems with this part.
2. Injectors
Yesterday, when i was accelerating to the fullest speed from highway paytoll i had massive power loss as if the engine was running out of gas or the injectors aren't firing anymore. I took out the spark plugs this morning and found that 3 were soaked in gasoline, and the fourth was unclean. I put tissue over each hole in the injector and when I turn the engine on without sparks, the three that have gazoline pop right out. The 4th one stays shut. I inspected the ground connection on ECU pins 14/55,30/55 and 48/55 i get 0ohm. I assume that the problem is in another location.
I also tried to reset the PID with no success. The car will start when the G28 is disconnected, but it is running fine with the G28 connected. However the intermittent misfire issue persists at higher RPM. The coolant sensor (G62), even when it is unplugged, shows temperatures of -49c. I also noticed that the oil pressure gauge in the cockpit shows audi keys replacement 2 bar while the actual pressure is 0.0 when I crank up the engine.
I'm not sure what to do. I feel like i've pretty much all other possibilities out. However, i'm afraid that i might have missed something. If anyone has any suggestions, please let me know! TIA!
3. Fuel Pump
The fuel pump in the g28 can be activated by a signal sent from the RPM sensor. The GM-style sender is identical to the G4 and both function in the 80 100 200, UrS and RS2 cars which is click here why you can easily locate one at a wrecking yard or at a parts store. It is simple to test them by putting your DMM in resistance mode and take measurements between pins 1 (with the bump on the connector's side up) and 2 (2nd from left on the black connector's end). They should be infinite Ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY ADU) engines requires to know click here the position and speed of the crankshaft in order to make a decision about timing of the fuel injector, etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 click here to accomplish this. If you encounter a problem with either one of these, the diagnostic scanner will show the codes audi a4 spare key that could trigger the engine shutting down.
A failing G28 sensor can cause an inaccurate gearbox speed counter or a gearbox that shifts more quickly than normal, or an unfire when in gear. It is possible that your sensor is failing and requires to be replaced if you experience any of these signs. They are cheap and easy-to-find particularly if they're a Bosch unit like ours. You can also choose the GM version of this component is also a good option.
5. Tachometer
A failing engine sensor could cause a number of problems in your vehicle. It's a crucial component of the transmission of your Audi, as it transmits information to the ECU on how fast or slowly the engine of the car is turning. If the sensor fails, it can cause problems for the transmission, as well as the rest of the car's components.
The G5 engine speed sensor is situated on the outside of the transmission, above the flywheel ring gear. It transmits a signal to the ECU at pin T55/49 through an uncolored wire. The ECU is then able to process the signal to control fuel, timig, and boost and then transmitting it to the G5 tachometer inside the instrument cluster. You can check for sensor failure by examining the 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 [79trace [79]) and between pin T6a/1 and pin T26a/12. You should observe approximately 1000 ohms resistance between those points. This is the same across the Audi 80-100-200-RS2 range, beginning with the 1985 MC and up to the 1997 UrS AN and the 1995 RS2 DU So, you may find them in wrecking yards.