Audi G28: The Good, The Bad, And The Ugly
Audi G28: The Good, The Bad, And The Ugly
Blog Article
How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician teaches you how to replace the G28 Engine Speed Sensor. The sensor is located near the edges of the transmission just 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 situated on the outside of the transmission, directly above the flywheel ring. The sensor sends signals through the grey wire to pin T55/49. The ECU utilizes this information to regulate the amount of fuel and boost. It also sends an indication to the G5 Tachometer in instrument cluster.
The sensor is used to link with the G40 Camshaft position Sensor. The ecu has to know when the crankshaft reached TDC, and where the camshaft lies in order to 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 line with the Intake Camshaft. It could also be a sign of a chain stretch or a jumpy chain link in the upper chain of timing. The code won't appear without the additional information supplied by other sensors (G4 or G40).
It can be a bit difficult to test as there are various pins on the connector, and each one has different functions. The best way to do it is by measuring the resistance between the ECU and the sensor. When the sensor is fully operational, it should be reading around 1000 ohms. Look for signs of coolant or oil in the connector bay if you are experiencing issues with this component.
2. Injectors
Yesterday, when i was accelerating to the fullest speed from highway paytoll i had an abrupt drop in power like the engine is running out of gas or injectors are not firing any more. I pulled out the spark plugs this morning, three were soaked in gasoline, and the fourth was unclean. I put a piece of tissue over each injector hole and when i turn the engine on without sparks, the three with gazoline jump out. The fourth one remains shut. I tested the ground connection on ECU pins 14/55, 30/55 and 48/55. I get zero ohm. I assume that the problem is somewhere else.
I also tried to reset the PID with no success. audi a3 key replacement The car will start when the G28 is unplugged, and it runs fine with the G28 connected. However the intermittent misfire issue continues to occur at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature value of -49c even when i unplug it. I also noticed that the oil gauge in the cockpit shows 2 bars when the actual pressure is zero.
I'm not certain what to do, but i feel i have pretty much ruled out everything else. I'm worried that i might have missed audi keys replacement something. Let me know if you have any ideas! 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 audi convenience key to the G4 what is the audi advanced key sender and both work on the 80,100,200, UrS, and RS2 vehicles. It is easy to find a spare in a wrecking shop or a parts store. Testing them is easy by putting your DMM in resistance mode and measure between pins 1 (with the bump on the connector's side up) and 2 (2nd from the left on the black connector's end). They should be infinite Ohms.
4. ECU
The ECU of our 20vt turbo (3B AAN ABY ADU) engines must know the position and speed the crankshaft in order to make a decision about timing of 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 lead to 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 while in gear. It is likely that your sensor is failing and needs to be replaced if you experience any of these symptoms. They are cheap and easy-to-find, especially in the case of an Bosch model like ours. If you prefer, GM's version of this part would be a good option.
5. Tachometer
A failing engine sensor could cause a myriad of issues within your vehicle. It's an essential 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. This sensor can cause the transmission to fail and other components of the car to be affected.
The G5 engine sensor is located at the outskirts of transmission, above the flywheel ring. It transmits an electrical signal through a gray wire to the ECU pin T55/49. The ECU utilizes this signal to control fuel and boost, and also to timigrate. It also sends it to the G5 Tachometer inside the instrument cluster. You can test the sensor for failure by examining the continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection replace audi key to pin T6a/1 (trace [79trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. You should observe approximately 1000 ohms resistance between these two points. 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 AAN and 1995 RS2 ADU so good ones might be availble in wrecking yards.