7 Simple Changes That Will Make A Big Difference With Your Audi G28
7 Simple Changes That Will Make A Big Difference With Your Audi G28
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How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. This sensor is situated at the edge of transmission just above the flywheel gear. It transmits a signal to the ECU via an uncolored wire (T55/49) which is then sent to the tachometer within the instrument cluster.
1. Engine Speed Sensor
The grey wire is located at the edges of the transmission, directly above the flywheel ring. The sensor transmits 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 an indication to the G5 tachometer in the instrument cluster.
The sensor serves as a reference point to connect with the G40 Camshaft Position Sensor. The ecu has to be aware of when the crankshaft has reached TDC and also the location of the camshaft in order to activate the spark and injectors.
If this sensor fails the ECU will display the P00160 error, which means the Crank Shaft and Intake Camshaft are out of sync, possibly indicating the chain is stretched or a jump link on the upper timing chain. However, the code won't be displayed on its own without additional information from other sensors (G4 and G40).
It's a bit tricky to test because there are various pins on the connector, and they all have different functions. The best way to do it is to measure the resistance between the ECU and the sensor. It should read about 1000 ohms when it is operating at its maximum. Look for signs of coolant or oil in the connector bay if you have issues with this part.
2. Injectors
Yesterday, while accelerating at full speed from the highway paytoll, i experienced an abrupt drop in power like the engine is out of gas or the injectors are not firing anymore. I took out the spark plugs this morning, 3 were drenched in gasoline and the fourth was dry. I put a piece of tissue over each injector hole, and when I start the engine with no sparks, the 3 with gazoline jump right out. The 4th one stays closed. I checked the ground connection on ECU pins 14/55,30/55 and 48/55 i get 0ohm. So i assume the problem is somewhere else.
I also tried to reset the PID but without success. The car will start audi spare key if the G28 is unplugged and runs fine when it is connected but it still is experiencing intermittent misfires at higher RPM. The coolant sensor (G62) even when it is unplugged, shows an ice temperature of -49c. I also noticed that the oil gauge in the cockpit shows 2 bar but the actual pressure is zero.
I'm not sure what to do, as i believe that i've eliminated everything else. I'm worried get more info that i might have missed something. Let me know if you have any ideas! TIA!
3. Fuel Pump
The fuel pump of the g28 gets a signal from the RPM sensor. The GM-style transmitter click here is the same as the G4 and both are used in the 80 100, 200, UrS and RS2 cars which is why you can easily locate one at a salvage yard or from a 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
Our 20vt turbo (3B AAN, ABY, and ADU) engines are equipped with an ECU that needs to be aware of the speed and position of the crankshaft to make a decision about timing of the fuel injectors, etc. In order to do this it utilizes 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.
Some of the symptoms of a failing G28 sensor are an inaccurate rev counter for the gearbox and gears that shift faster than normal and/or misfiring when in gear. It is probable that the sensor is failing and needs to be replaced if you notice any of these symptoms. The good thing is that they are very affordable and easy to find, especially when you're looking at the Bosch unit which is what ours are. Alternately, GM's version this part is an excellent choice.
5. Tachometer
A faulty engine speed sensor could be the cause of a slew of issues in your car. It's a crucial component of the transmission in your Audi, as it transmits information to the ECU regarding how fast or slowly the car's engine is turning. If this sensor fails, it will cause problems for the transmission as well as the other car's components.
The G5 engine sensor is located at the outskirts of the transmission, just above the flywheel ring. It sends signals via an uncolored wire to the ECU pin T55/49. The ECU is then able to process this signal to control fuel, timig, and boost, and also sends it on to the G5 tachometer inside the instrument cluster. You audi spare keys 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 on pin T6a/1 (trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. You should see approximately 1000 ohms of resistance between those points. This is a standard component across the Audi 80, 100, 200, UrS and RS2 range from 1985 MC spare audi key until the 1997 UrS AAN and 1995 RS2 ADU. Good ones might be availble in wrecking yards.