10 Things You'll Need To Be Aware Of Audi G28
10 Things You'll Need To Be Aware Of Audi G28
Blog Article
How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician shows you how to replace the G28 Engine Speed Sensor. The sensor is located on the outside of the transmission over the flywheel gear. It sends a message to the ECU via an uncolored wire T55/49, then to the tachometer on the instrument cluster.
1. Engine Speed Sensor
The grey wire is located at the edges of the transmission, just above the flywheel ring. The sensor sends signals through the grey wire to pin T55/49. The ECU then utilizes this information to regulate fuel, timig and boost. It also sends an alert to the G5 Tachometer within the instrument cluster.
The sensor is used as a reference for comparing with the G40 Camshaft Position Sensor. The ecu needs to be aware of when the crankshaft has reached TDC, and the location of the camshaft 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 not in alignment with the Intake Camshaft. It could also indicate a chain stretch or a jumped chain link in the upper chain. The code won't appear without the additional information provided by other sensors (G4 or G40).
Testing is a bit challenging since there are two connector pins and they perform different functions but the best method of testing it is to measure resistance between the sensor and the ECU. It should read around 1000 ohms when it is at full operation. Look for signs of coolant, or oil in the connector bay if you are experiencing issues with this part.
2. Injectors
Yesterday, as i was accelerating off the highway paytoll at maximum speed I noticed a significant decrease in power. It was as if the engine had run out of gas. Or my injectors weren't firing. I took out the spark plugs this morning, 3 were soaked in gasoline, and the fourth was unclean. I placed a tissue over each injector hole, and when i start the engine without sparks, the ones with gazoline jump out. The 4th one remains closed. I tested the ground connection of ECU pins 14,30, and 48/55. I got 0ohm. I'm assuming the issue is in another place.
I also tried to reset the PID but with no luck. The car can start if the G28 is unplugged and it runs perfectly when it is connected however it here has the intermittent misfire issue at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature value of -49c, even if I unplug it. I also noticed that the oil gauge in the cockpit shows audi tt keys 2 bars while the actual pressure is 0.
I'm not sure what to do, i feel i have pretty much eliminated everything else. But i'm worried that I might have missed something. If anyone has any suggestions, please chime in! TIA!
3. Fuel Pump
The fuel pump on the g28 is activated by a signal by 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 click here salvage yard or in a local 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 side up) and 2 (2nd from the left on the black end of the connector). They must be infinite ohms.
4. ECU
Our 20vt turbo (3B AAN, ABY, and ADU) engines are equipped with an ECU that must know the speed and position of the crankshaft in order to make decisions about timing of the fuel injector, for example. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these go badly, you will see codes on the diagnostic scanner that could cause engine shut down.
A damaged G28 sensor could result in an inaccurate speed counter for your gearbox or a gearbox that shifts faster than normal, and/or a misfire while in the gear. If you are experiencing any of these issues it is likely that your sensor is going bad and requires replacement. They are cheap and easy-to-find, especially in the case of a Bosch unit like ours. Alternately, GM's version this component is a good option.
5. Tachometer
A malfunctioning engine sensor can cause a myriad of issues within your vehicle. It's a vital component of the Audi's transmission because it communicates to the ECU about how the car's crankshaft is spinning. If the sensor fails, it will cause problems for the transmission as well as the other car's components.
The G5 engine speed sensor is situated on the outside of the transmission just above the flywheel ring gear and sends a signal directly to the ECU at pin T55/49 via a more info grey wire. The ECU then uses and processes the signal to control fuel, timig, and boost as well as sends it on to the G5 Tachometer located in the instrument cluster. You can determine if the sensor is in failure by examining the continuity from the sensor to the tachometer. Additionally, you can check continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]), and between pin T6a/1 as well as pin T26a/12. You should detect the resistance to be around 1000 ohms between these two points. This is a typical component across the Audi 80 100, 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU, so the best check here ones might be availble in wrecking yards.