"The Ultimate Cheat Sheet On Audi G28
How to Replace an Audi G28 Engine Speed SensorIn this video, Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. This sensor is located at the edge of transmission over the flywheel gear. It sends a message to the ECU through the grey wire T55/49 and then to the tachometer on the instrument cluster.
1. Engine Speed Sensor
The sensor is located at the edge of the transmission, above the flywheel ring gear G28 Engine Speed Sensor sends signals to ECU pin T55/49 via a grey wire. The ECU then uses this information to control the flow of fuel, timig and boost. It also sends signals to the G5 Tachometer located in the instrument cluster.
The sensor is used as a reference for comparing with the G40 Camshaft Position Sensor. The ecu has to know when the crankshaft has reached TDC, and where the camshaft lies so that it can 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 not in sync, possibly indicating chain stretch or a jumped link on the upper chain of timing. The code won't show without the additional information supplied by other sensors (G4 or G40).
Testing can be a bit difficult since there are two connector pins, and they perform different functions but the best method of testing it is by measuring resistance between the sensor and the ECU. When the sensor is operational, it should be reading around 1000 ohms. If you are having problems with this part, check for evidence of coolant or oil in the connector bay.
2. Injectors
Yesterday, while accelerating at full speed from the highway paytoll, i experienced a big cut in power like the engine is out of gas or injectors aren't firing at all. In the morning, i removed the spark plugs. Three were drenched with gazoline the 4th one was dry. I put a piece of tissue over each injector hole and when i turn the engine on without sparks, the 3 with gazoline jump right out. The fourth one remains closed. I checked the ground connection of ECU pins 14,30, and 48/55. I got 0ohm. I'm assuming the issue is somewhere else.
I also tried to reset PID without success. The car will start when the G28 is unplugged, and it is running fine with the G28 connected. However the intermittent misfire issue persists at higher RPM. The coolant sensor (G62) even when check here unplugged, still shows a temperature of -49c. Also, i noticed that the gauge for oil pressure in the cockpit is showing 2 bar while the actual pressure is 0.0 when I crank up the engine.
I audi keys replacement don't know what to do. I feel like i've pretty much all other possibilities out. I'm concerned that i may have missed something. If anyone has any suggestions, please chime in! TIA!
3. Fuel Pump
The fuel audi replacement key uk pump in the g28 can be activated by a signal sent by the RPM sensor. The GM-style transmitter functions similarly to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. You can easily locate an extra in a wrecking shop or a parts store. Testing them is easy by putting your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector's side up) and 2 (2nd from the left on the black connector's side). They must be infinite Ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY) engines must know the position and speed the crankshaft in order to make a decision about fuel injector timing, etc. In order to do this it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you are experiencing issues with either of these sensors, the diagnostic scanner will show codes that could lead to an engine shutdown.
A damaged G28 sensor could result in an inaccurate speed counter for your gearbox and a gearbox which shifts more quickly than normal, or a misfire in the gear. It is likely that your sensor is failing and needs to be replaced if you experience any of these symptoms. The website good news is they are very cheap and easy to find, especially if you're looking at a Bosch model, like ours. Alternately, the GM version of this component is also a good choice.
5. Tachometer
A malfunctioning engine speed sensor could be the reason behind numerous issues in your car. It's a vital component of your Audi's transmission, since it relays information to the ECU about how fast or slow the vehicle's crankshaft is turning. When this sensor fails, it will cause problems for 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 fuel, timig and boost and then sends it on to the G5 tachometer inside the instrument cluster. You can check for sensor failure by examining the continuity of the sensor to the tachometer. Also, you can verify 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. You should observe approximately 1000 ohms resistance between those two pins. This is a common part that is found across the Audi 80 100 200, UrS and RS2 range from 1985 MC through the 1997 UrS audi spare key replacement AAN and 1995 RS2 ADU, so the best ones could be available in wrecking yards.