Audi G28: 10 Things I'd Like To Have Learned In The Past
Audi G28: 10 Things I'd Like To Have Learned In The Past
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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. The sensor is located near the edges of the transmission just above the flywheel ring gear. It sends a signal to the ECU via the grey wire (T55/49) which is then sent 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 the G28 Engine Speed Sensor sends a signal to ECU pin T55/49 via the grey wire. The ECU utilizes this information to regulate fuel and boost. It also sends a signal to the G5 Tachometer located in the instrument cluster.
The sensor serves as a reference to correlate 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 display a P00160 error message. This indicates that the Crank Shaft is out of sync with the Intake Camshaft. It could also indicate 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).
It is a little tricky to test as there are different pins on the connector, and they all have different functions. The best method for doing this is to measure the resistance between the ECU and the sensor. When the sensor is fully functional, it should read approximately 1000 ohms. Examine for signs of coolant or oil in the connector bay if you have problems with this part.
2. Injectors
Yesterday, while accelerating from the highway paytoll at maximum speed, i noticed a huge drop in power. It was as if the engine had run out of gas. Or, my injectors weren't firing. This morning i pull out the spark plugs, three were soaked with gazoline and the fourth one was dry. When I crank the engine with no sparks i put tissue on the top of each hole in the injector and the 3 that were drenched in gazoline pop out, but the 4th one stays shut. I tried to test the ground connections of ECU pins 14,30, and 48/55. I found 0ohm. Therefore, i think the issue is elsewhere.
I also tried to reset the PID but without success. get more info The car will start when the G28 is unplugged, and it runs fine with the G28 plugged in. However, the intermittent misfire problem continues to occur at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature of -49c even when i unplug it. I also noticed that the oil gauge in the cockpit shows 2 bar while the actual pressure is 0.
I'm not certain what to do, i think i've pretty much completely ruled out all other possibilities. But i'm worried that i might have missed something. If anyone has suggestions, please chime in! TIA!
3. Fuel Pump
The fuel pump on the g28 is activated by 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, click here and RS2 vehicles. It is easy to find a spare in a wrecking shop or parts store. It is easy to test them: simply put your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump at the connector end facing upwards). They should be infinite ohms.
4. ECU
The ECU of our 20vt turbo (3B AAN ABY) engines needs to be aware of the position and speed of the crankshaft to make decisions regarding timing of the fuel injector, etc. In order to do this read more it uses a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you encounter a problem with either of these sensors, the diagnostic scanner will display the codes that could trigger an engine shutdown.
Some of the signs of a malfunctioning G28 sensor include an inaccurate gearbox rev counter, gears shifting quicker than normal and/or a misfire when you're in gear. If you experience any of these issues, it is likely that here your sensor is going bad and needs replacing. The good news is they are quite affordable and easily accessible particularly if you're looking at an Bosch model, which is what we have. You can also choose the GM version of this unit is also a great option.
5. Tachometer
A failing engine sensor could cause a myriad of issues within your vehicle. It is an important part of the transmission in 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 could disrupt the performance of the transmission, as well as the rest of the car's components.
The G5 engine speed sensor is located at the outside of the transmission, above the flywheel ring gear and sends a signal directly 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 inside the instrument cluster. You can check for sensor failure by checking continuity from the sensor to the tachometer. Also, you can check continuity between pin 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. It should show approximately 1000 ohms resistance between those two pins. This is a common feature across the Audi 80-100-200-RS2 series, starting from the 1985 MC all the way up to the 1997 UrS AN and the 1995 RS2 audi spare key replacement Du, so you might find good ones in wrecking yards.