Ten Things You Learned In Kindergarden That Will Help You Get Audi G28
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 situated at the top 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 in the instrument cluster.
1. Engine Speed Sensor
The grey wire is located on the edge of transmission, just above the flywheel ring. The sensor transmits signals through the grey wire to pin T55/49. The ECU then uses this information to control fuel, timig and boost. It also sends an alert to the G5 Tachometer located in the instrument cluster.
The sensor is used to correlate 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 means that the Crank Shaft is not in alignment with the Intake Camshaft. It could also be a sign of the possibility of a chain stretch or jumpy chain link in the upper chain. The code won't appear without the additional information supplied by other sensors (G4 or G40).
It can be a bit difficult to test because there are several pins on the connector and each one has different functions. The best way to do it is to measure the resistance between the ECU and the sensor. If the sensor is functional, it should read about 1000 ohms. If you are having problems with this component, look for signs of oil or coolant in the connector bay.
2. Injectors
Yesterday, while accelerating at full speed from the highway paytoll, I experienced massive power loss as if the engine was running out of gas or the injectors are not firing anymore. I took out the spark plugs this morning, three were drenched in gasoline and the fourth was unclean. I put tissue over each injector hole and when i start the engine with no sparks, the three with gazoline jump right out. The 4th one stays shut. I tested the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I got 0ohm. I'm assuming that the issue is somewhere else.
I also tried to reset the PID but without success. The car will start when the G28 is unplugged, and it works fine when the G28 plugged in. However, the intermittent misfire problem continues to occur at higher RPM. The coolant sensor (G62) even when it is unplugged, shows temperatures of -49c. I also noticed that the oil gauge in the cockpit shows 2 bar when the actual pressure is zero.
I don't know what to do. I believe that I've all other possibilities out. But i am afraid I might have missed something. If anyone has suggestions, please let me know! TIA!
3. Fuel Pump
The fuel pump in the g28 can be activated by a signal sent from the RPM sensor. The GM-style transmitter is the same as the G4 and they both work in the 80 100 200, UrS and RS2 cars which is why you can easily locate one at a wrecking yard or from a parts store. Testing them is easy - 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 the left on the black end of the connector). They should be infinite Ohms.
4. ECU
The ECU of our 20vt turbo (3B AAN ABY) engines must 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 encounter a problem with either of these, the diagnostic scanner will show the codes that could trigger the engine shutting down.
A damaged G28 sensor could result in an inaccurate gearbox speed counter or a gearbox that shifts faster than normal, or an unfire when in gear. If you are experiencing any of these issues, it is most likely that your sensor is going bad and needs replacing. The good thing is that they are quite affordable and easy to find particularly when you're looking at the Bosch sensor, like ours. You can also choose the GM version of this component is also a good option.
5. Tachometer
A malfunctioning engine sensor can cause a myriad of issues in your car. It's an essential component of the transmission in your Audi because it relays information to the ECU regarding how fast or slow the engine is spinning. If this sensor fails, it will cause problems for the transmission as well as the rest of the car's components.
The G5 engine sensor is located near the edge of the transmission, just above the flywheel ring. It sends an electrical signal through an uncolored wire to the ECU pin T55/49. The ECU uses this signal to control the amount of fuel and boost, as well as timig. It also transmits it to the G5 Tachometer located in the instrument cluster. You can test the sensor for any failure by checking the continuity between it and the tachometer. You can also check continuity between ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. You should see around 1000 ohms of resistance between those two pins. audi a3 key The Keylab is a standard component across the Audi 80, 100, 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU so good ones could be available in wrecking yards.