7 Small Changes That Will Make An Enormous Difference To Your Audi G28
7 Small Changes That Will Make An Enormous Difference To Your Audi G28
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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. This sensor is situated at the edge of transmission, above the flywheel gear. It sends a message to the ECU through a grey wire T55/49, then to the tachometer on the instrument cluster.
1. Engine Speed Sensor
The sensor is located at the edge of the transmission just above the flywheel ring gear G28 Engine Speed Sensor sends an electrical signal to ECU pin T55/49 through an uncolored wire. The ECU then utilizes this information to regulate the flow of fuel, timig and boost. It also sends an alert to the G5 Tachometer located in the instrument cluster.
The sensor is used to connect the G40 Camshaft position Sensor. The ecu must know when the crankshaft has reached TDC and also the location of the camshaft so that it can activate the spark and injectors.
If this sensor fails, the ECU will display a P00160 error message. This indicates that the Crank Shaft is out of alignment with the Intake Camshaft. It could also indicate an issue with the chain or a jumped chain link in the upper chain. The code will not appear without the additional information provided by other sensors (G4 or G40).
It's a bit tricky to test because there are several pins on the connector, and each one has different functions. The best method for doing this is by measuring the resistance between the ECU and the sensor. It should read around 1000 ohms if the sensor is at full operation. If you're experiencing issues with this sensor, look for signs of oil or coolant in the connector bay.
2. Injectors
Yesterday, while accelerating from the highway paytoll at full speed, i noticed a huge decrease in power. It was as if the engine had run out of gas. Or, my injectors weren't firing. In the morning, i removed the spark plugs. Three were drenched with gazoline the 4th one was dry. I put tissue over each injector hole and when i turn the engine on without sparks, the 3 with gazoline jump right out. The 4th one stays shut. I inspected the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I got zero ohm. So i assume the problem is somewhere else.
I also tried to reset the PID without success. The car is able to start if the G28 is disconnected more info and is running fine when it is plugged in, but still has the intermittent misfire issue at higher RPM. The coolant sensor (G62) even if it is not plugged in, shows temperatures of -49c. I get more info also noticed that the oil pressure gauge in the cockpit shows 2 bar while the actual pressure is 0.0 when i rev the engine.
I'm not certain what to do, but i think i've pretty much completely ruled out all other possibilities. I'm afraid i may have missed something. If anyone has any ideas please share them! TIA!
3. Fuel Pump
The fuel pump in the g28 is activated by a signal sent by the RPM sensor. The GM-style transmitter is similar to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. You can easily find the spare in a salvage shop or a parts store. Test them out - put your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector's end up) and 2 (2nd from left on the black connector's end). 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 decisions about fuel injector timing etc. To accomplish 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 display codes that could cause an engine shut down.
A malfunctioning G28 sensor could cause an inaccurate gearbox speed counter or a gearbox that shifts more quickly than normal, or a misfire in the gear. If you are experiencing any of these issues, it is likely that your sensor is failing and needs replacing. The good news is that they are very cheap and easy to find, especially if you're looking at click here the Bosch unit which is what ours are. Alternately, the GM version of this unit is also a good choice.
5. Tachometer
A faulty engine speed sensor could be a cause for numerous issues in your car. It's an essential component of your Audi's transmission, since it relays information to the ECU about how the car's crankshaft is spinning. If the 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, 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 the signal to control the flow of fuel, timig and boost as well as transmitting it to the G5 tachometer inside the instrument cluster. You can determine if the sensor is in failure by examining the continuity of the sensor to the tachometer. Additionally, you can examine the continuity between pins T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]) and between pin more info T6a/1 and pin T26a/12. It should show approximately 1000 ohms resistance between these two points. This is a standard component across the Audi 80 100, 200, UrS and RS2 range from 1985 MC until the 1997 check here UrS AAN and 1995 RS2 ADU. Good ones could be available in wrecking yards.