The 3 Biggest Disasters In Audi G28 History
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. This sensor is located near the transmission's edge over the flywheel gear. It transmits a signal to the ECU via the grey wire (T55/49), then to the tachometer in the instrument cluster.
1. Engine Speed Sensor
It is located on the outside of the transmission, above the flywheel ring gear G28 Engine Speed Sensor sends a signal to ECU pin T55/49 via an uncolored wire. The ECU then uses this information to control the flow of fuel, timig and boost. It also sends signals to the G5 Tachometer located in the instrument cluster.
The sensor is used to link with the G40 Camshaft position Sensor. The ecu must be aware when the crankshaft is TDC and where the camshaft is located so that it can start spark and injectors according to the situation.
If this sensor fails, the ECU will display an error code P00160. spare audi key cost indicates that the Crank Shaft is out of line with the Intake Camshaft. It could also indicate an issue with the chain or a jumped chain link in 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 tricky because there are two pins for the connector and they have different functions but the best way to test it is to measure resistance between the sensor and the ECU. If the sensor is operational, it should read approximately 1000 ohms. Examine for signs of coolant or oil in the connector bay if you are experiencing issues with this component.
2. Injectors
Yesterday, as i was accelerating off the highway paytoll at full speed, i noticed a huge drop in power. It was like the engine had run out of gas. Or, replacement audi key weren't firing. I took out the spark plugs this morning, three were soaked in gasoline, and the 4th was dry. I put a piece of tissue over each injector hole, and when I start the engine without sparks, the 3 that have gazoline pop right out. The 4th one stays shut. I tested the ground connection on ECU pins 14/55, 30/55 and 48/55. i get 0ohm. Therefore, i think the issue is in another place.
I also tried to reset the PID without success. The car is able to start if the G28 is unplugged and it runs perfectly when it is plugged in but it still is experiencing intermittent misfires at higher RPM. The coolant sensor (G62) even if it is not plugged in, shows an ice temperature of -49c. I also noticed that the oil gauge in the cockpit shows 2 bar but the actual pressure is 0.
I'm not sure what to do. I feel like i've pretty much ruled everything else out. I'm concerned that i may have missed something. If anyone has suggestions, please chime in! TIA!
3. Fuel Pump
The fuel pump in the g28 gets a signal from the RPM sensor. The GM-style transmitter is identical to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. It is easy to find an extra in a wrecking shop or 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 end up) and 2 (2nd from left on the black connector's side). They should be infinite Ohms.
4. ECU
The ECU of our 20vt turbo (3B AAN ABY ADU) engines needs to know the speed and position of the crankshaft to make decisions regarding timing of fuel injectors, etc. In order to do this it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you have a problem with either of these sensors, the diagnostic scanner will show the codes that could trigger an engine shut down.
Some of the signs of a failing G28 sensor are an inaccurate rev counter for the gearbox the gears are shifting faster than normal and/or a misfire when in gear. If you experience any of these issues, it is likely that your sensor is going bad and should be replaced. The good news is that they are very cheap and readily available particularly in the case of an Bosch sensor, like ours. Alternatively, GM's version of this part is an excellent choice.
5. Tachometer
A faulty engine speed sensor could be the cause of a slew of issues with your vehicle. It's a crucial component of the transmission in your Audi because it relays information to the ECU about how fast or slowly the car's engine is spinning. This sensor could cause the transmission to fail and other components of the car to be affected.
The G5 engine speed sensor is situated on the outside of the transmission, above the flywheel ring gear and transmits a signal to the ECU at pin T55/49 via a grey wire. The ECU then uses and processes this signal to control the flow of fuel, timig and boost, and also 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 on pin T6a/1 (trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. There should be the resistance to be around 1000 ohms between these points. This is the same across the Audi 80-100-200-RS2 model, ranging from the 1985 MC up to the 1997 UrS AN and the 1995 RS2 Du So, you may find some good ones in wrecking yards.