4 Dirty Little Secrets About Audi G28 Industry Audi G28 Industry
4 Dirty Little Secrets About Audi G28 Industry Audi G28 Industry
Blog Article
How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician teaches how to replace the G28 Engine Speed Sensor. This sensor is located on the edge of the transmission, above the flywheel ring gear. It transmits a signal to the ECU via an uncolored wire T55/49, then to the tachometer located on the instrument cluster.
1. Engine Speed Sensor
The grey wire is located on the edge of transmission, above the flywheel ring. The sensor sends an electrical signal through the grey wire to pin T55/49. The ECU uses this information to regulate boost and fuel. It also sends an indication to the G5 Tachometer in instrument cluster.
The sensor is used as a reference point to connect 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 activate spark and injectors according to the situation.
If this sensor fails to function, the ECU will display a P00160 error message. This means that the Crank Shaft is out of line with the Intake Camshaft. It could also be a sign of a chain stretch or a jumped chain link in the upper timing chain. The code won't appear without the additional information provided by other sensors (G4 or G40).
Testing is a bit tricky because there are two connector pins and they perform different functions but the most effective way to test it is to measure resistance between the sensor and the ECU. It should read approximately 1000 ohms when it is operating at its maximum. If you're experiencing issues with this part, check for evidence of coolant or oil in the connector bay.
2. Injectors
Yesterday, when accelerating from highway paytoll at a high speed I noticed a massive drop in power. It was like the engine had run out of gas. Or my injectors weren't firing. This morning i pull out the spark plugs, three were drenched with gazoline the fourth one was dry. When i crank the engine without sparks, I put a piece of tissue on the top of each hole in the injector, the 3 drenched with gazoline jump out but the 4th stays shut. I tested the ground connection of ECU pins 14,30 and 48/55. I got 0ohm. I'm assuming the issue is elsewhere.
I also tried to reset the PID but without success. The car can start if the G28 is not plugged in and replacement key for audi a4 is running fine when it is plugged in, but still has intermittent misfire issues at higher RPM. The coolant sensor (G62), even when unplugged, still shows an ice temperature of -49c. Also, i noticed that the oil pressure gauge in the cockpit is showing 2 bar when the actual pressure is 0.0 when I crank up the engine.
I'm not sure what to do. I feel like i've pretty much all other possibilities out. I'm worried that i might have missed something. If anyone has any suggestions, please share them! TIA!
3. Fuel Pump
The fuel pump of the g28 receives a signal from the RPM sensor. The GM-style sensor read more is identical to the G4 and both function in the 80, 100 200, UrS and RS2 cars so you can easily find one at a salvage yard or from a parts store. It is easy to test them: simply put your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump at the connector end facing up). They should be infinite Ohms.
4. ECU
Our 20vt turbo (3B, AAN, ABY and ADU) engines are equipped with an ECU that has to be aware of the speed and position of the crankshaft to make a decision about fuel injector timing etc. In order to do this 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 codes that could cause the engine shutting down.
A malfunctioning G28 sensor can cause an inaccurate gearbox speed counter or a gearbox that shifts faster than normal, and/or an unfire when in the gear. If you are experiencing any of these issues, it is most likely that your sensor is deteriorating and should be replaced. The good news is they are very cheap and easy to find, especially if you're looking at a Bosch model, like ours. You can also choose the GM version of this unit is also a good option.
5. Tachometer
A failing engine speed sensor could be the cause of numerous issues with your car. It is a crucial part here of your Audi's transmission, since it relays information to the ECU about how the car's crankshaft is turning. When this sensor fails, it will 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 just above the flywheel ring gear. It sends a signal 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 and then sends it on to the G5 tachometer inside the instrument cluster. You can determine if the sensor is in failure by examining the continuity from the sensor to the tachometer. Also, 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 T6a/1 as well check here as pin T26a/12. You should see around 1000 ohms of resistance between those points. This is read more a standard component across the Audi 80 100 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU so good parts could be found in wrecking yards.