What Do You Think? Heck What Is Audi G28?
What Do You Think? Heck What Is Audi G28?
Blog Article
How to Replace an Audi G28 Engine Speed Sensor
In this video, Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. This sensor is located near the edges of the transmission, above the flywheel ring gear. It transmits a signal the ECU via the grey wire (T55/49), then to the tachometer within the instrument cluster.
1. Engine Speed Sensor
It is located on the outside of the transmission above the flywheel ring gear, the G28 Engine Speed Sensor sends a signal to ECU pin T55/49 through a grey wire. The ECU uses this information to regulate the amount of fuel and boost. It also sends an indicator to the G5 Tachometer located in the instrument cluster.
The sensor serves as a reference for comparing with the G40 Camshaft Position Sensor. The ecu must be aware when the crankshaft is TDC and where the camshaft is so it can activate spark and injectors in the right way.
If this sensor fails the ECU will show an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are not in sync and possibly indicating chain stretch or a jumped link on the upper timing chain. The code won't show without the additional information supplied by other sensors (G4 or G40).
Testing can be a bit difficult as there are two different connector pins, and they have different functions but the most effective way to test it is by measuring resistance between the sensor and the ECU. If the sensor is functional, it should read about 1000 ohms. Look for signs of coolant, or oil in the connector bay if there are problems with this part.
2. Injectors
Yesterday, when accelerating from highway paytoll at a high speed, i noticed a huge reduction in power. It was like the engine was running out of gas. Or, my injectors were not firing. I took out the spark plugs this morning, three were drenched in gasoline and the fourth was dry. When i crank the engine without sparks i put tissue on the top of each hole in the injector, the 3 drenched with gazoline leap out, however the 4th stay closed. I tested the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ i get zero ohm. I'm assuming the issue is elsewhere.
I also tried to reset the PID without success. The car can start when the G28 is unplugged and it runs perfectly when it is connected but it still has intermittent misfire issues at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature of -49c even when i unplug it. Also, i noticed that the gauge for oil pressure in the cockpit is showing 2 bar while the actual pressure is 0.0 if i crank up the website engine.
I'm not sure what to do. I think I've all other possibilities out. I'm afraid i may have missed something. If anyone has any ideas please chime in! TIA!
3. Fuel Pump
The fuel pump get more info in the g28 receives signals from the RPM sensor. The GM-style transmitter is similar to the G4 sender and works on the 80,100,200, UrS, and RS2 vehicles. It is easy to find an extra in a wrecking website shop or parts store. It is easy to test them - simply switch your DMM into resistance mode and test the distance between pins 1 and 2 (with the bump at the connector's end facing up). 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 here fuel injector timing etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these sensors go bad you will get codes on the diagnostic scanner which could cause engine shut down.
A malfunctioning G28 sensor could result in an inaccurate gearbox speed counter and a gearbox which shifts faster than normal, or an unfire when in the gear. If you experience any of these issues, it is likely that your sensor is deteriorating and requires replacement. The good news is that they are very affordable and easily accessible particularly when you're looking at the Bosch unit which is what we have. Alternatively, the GM version of this component is also a good option.
5. Tachometer
A malfunctioning engine sensor can cause a variety of issues in your car. It's a vital component of your Audi's transmission, as it sends information to the ECU about how fast or slow the car's crankshaft is rotating. If the sensor fails, it could affect the performance of the transmission and the other car's components.
The G5 engine speed sensor is located at the edge of the transmission above the flywheel ring gear. It sends a signal directly to the ECU at pin T55/49 via a grey wire. The ECU uses this signal to regulate the amount of fuel and boost, as well as timig. It also transmits it to the G5 Tachometer located in the instrument cluster. You can test the sensor for any failure by checking the continuity between it and the tachometer, between ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. You should detect a resistance of approximately 1000 ohms between these read more points. This is a standard component across the Audi 80 100 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU. Good ones could be available in wrecking yards.