The Most Pervasive Issues In Audi G28
The Most Pervasive Issues In Audi G28
Blog Article
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 on the outside of the transmission over the flywheel gear. It sends a signal to the ECU via a grey wire (T55/49) and then to the tachometer located in the instrument cluster.
1. Engine Speed Sensor
The grey wire is located on the edge of transmission, above the flywheel ring. This sensor sends a signal via the grey wire to pin T55/49. The ECU then uses this information to control fuel, timig and boost. It also sends signals to the G5 Tachometer located in the instrument cluster.
The sensor is used as a reference point to connect with the G40 Camshaft Position Sensor. The ecu has to know when the crankshaft reached TDC and also the position of the camshaft, so that it can activate the spark and injectors.
If this sensor fails, the ECU will show an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are out of sync and could indicate chain stretch or a jumped link on the upper timing chain. The code won't show without the additional information provided by other sensors (G4 or G40).
Testing is a bit tricky since there are two pins for the connector and they have different functions but the most effective method of testing it is by measuring resistance between the sensor and the ECU. When the sensor is functional, it should read about 1000 ohms. If you're experiencing issues with this component, look for signs of coolant or oil in the connector bay.
2. Injectors
Yesterday, as i was accelerating off the highway paytoll at a high 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. This morning i pull out the spark plugs. Three were drenched in gazoline, the fourth one was dry. I put a piece of tissue over each injector hole and when i start the engine with no sparks, the ones with gazoline jump out. The fourth one remains closed. I checked the ground connection of ECU pins 14,30, and 48/55. I found zero ohm. I'm assuming the issue is somewhere else.
I also tried to reset the PID without success. The car more info will start when the G28 is disconnected, but it runs fine with the G28 connected. However the intermittent misfire issue still occurs at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature value of that is -49c even after unplugging it. Also i noticed that the oil pressure gauge in the cockpit shows 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 afraid i may have missed something. Let me know should you have any suggestions! TIA!
3. Fuel Pump
The fuel pump in the g28 receives a signal from the RPM sensor. The GM-style sender is the same as the G4 and both are used in the 80 100 200, UrS and RS2 cars which is audi replacement key why you get more info can easily locate one at a junkyard or from a parts store. It is easy to test them - simply switch your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump at the connector end facing upwards). They must be infinite Ohms.
4. ECU
Our 20vt turbo (3B AAN, ABY and ADU) engines have an ECU that must know the speed and position of the crankshaft in order to make a decision about fuel injector timing etc. To accomplish this, it uses a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these go badly, you will see codes on the diagnostic scanner which can cause the engine to shut down.
A failing G28 read more sensor can cause an inaccurate speed counter for the gearbox or a gearbox that shifts more quickly than normal, or a misfire in the gear. It is possible that the sensor is failing and requires to be replaced if you notice any of these symptoms. The good news is they are quite affordable and readily available, especially in the case of the Bosch unit which is what ours are. Alternatively, GM's version of this part would be an option.
5. Tachometer
A damaged engine sensor could cause a myriad of issues in your car. It's an essential component of the Audi's transmission as it sends information lost audi keys to the ECU about how the car's crankshaft is rotating. If this sensor fails, it could cause problems for the transmission and the other car's components.
The G5 engine speed sensor is located at the edge of the transmission just above the flywheel ring gear and sends a signal to the ECU at pin T55/49 via a grey wire. The ECU then uses and processes this signal to regulate fuel, timig, and boost and then sends it on to the G5 Tachometer located in the instrument cluster. You can check the sensor for failure by examining the continuity between it and the tachometer, between ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. You should see approximately 1000 ohms resistance between these two points. This is a common component across the Audi 80 100 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU so good ones might be availble in wrecking yards.