How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. The sensor is situated on the edge of the transmission just above the flywheel ring gear. It transmits a signal to the ECU through an uncolored wire T55/49, then to the tachometer located on the instrument cluster.
1. Engine Speed Sensor
It is located on the outside of the transmission above the flywheel ring gear the G28 Engine Speed Sensor sends an electrical signal to ECU pin T55/49 using the grey wire. The ECU utilizes this information to regulate the amount of fuel and boost. It also sends an indication to the G5 tachometer inside the instrument cluster.
The sensor is used as a reference to correlate with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft is TDC and the location of the camshaft so it can activate spark and injectors in the right way.
If this sensor fails when it fails, the ECU will display an error code P00160. This indicates that the Crank Shaft is out of alignment with the Intake Camshaft. It could also be a sign of a chain stretch or a jumped 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's a bit tricky to test since there are several connector pins, and each has its own functions. The best method for doing this is to measure the resistance between the ECU and the sensor. When the sensor is operational, it should be reading about 1000 ohms. If you are having problems with this part, check for signs of oil or coolant in the connector bay.
2. Injectors
Yesterday accelerating full speed from highway paytoll i had massive power loss like the engine is running out of gas or the injectors are not firing anymore. In the morning, i removed the spark plugs, three were drenched with gazoline the fourth was dry. 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 stays closed. I tried to test the ground connections of ECU pins 14,30, and 48/55. I found zero ohm. I'm assuming that the issue is somewhere else.
I also tried to reset the PID without success. The car can start when the G28 is disconnected and runs fine when it is plugged in however it is experiencing intermittent misfires at higher RPM. The coolant sensor (G62) even when unplugged, still shows temperatures of -49c. I also 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 i have pretty much completely ruled out all other possibilities. But i'm worried that I may have missed something. If anyone has any suggestions, please chime in! TIA!
3. Fuel Pump
The fuel pump in the g28 receives a signal from the RPM sensor. The GM-style sender is identical to the G4 and both are used in the 80, 100 200, UrS and RS2 cars so you can easily find one at a junkyard or from a parts store. Test them out - put your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the more info connector end up) and 2 (2nd from the left on the black connector's side). They should be infinite Ohms.
4. ECU
Our 20vt turbo (3B, AAN, ABY and ADU) engines have an ECU that must know the speed and position of the crankshaft in order to make decisions regarding timing of the fuel injectors, etc. To accomplish this, it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either how much is a replacement audi key of these goes bad you will get codes on the diagnostic scanner which can lead to engine shutdown.
A malfunctioning G28 sensor could result in an inaccurate speed counter for the gearbox or a gearbox that shifts faster than normal, or an unfire when in gear. It is likely that your sensor is check here failing and requires to be replaced if you experience any of these symptoms. The good thing is that they are very affordable and easily accessible particularly in the case of an Bosch unit which is what we have. You can also choose the GM version of this component is also a good option.
5. Tachometer
A faulty engine speed sensor could be a cause for numerous problems in your car. It is an important part of audi a3 replacement key the transmission of your Audi since it sends information to the ECU regarding how fast or slowly the engine of the car is turning. This sensor can cause the transmission to malfunction and other car components to be affected.
The G5 engine sensor is located near the edge of transmission, above the flywheel ring. It transmits signals via a gray wire to the ECU pin T55/49. The ECU is then able to process the signal to control the flow of fuel, timig and boost and then transmitting it to the G5 audi a4 car key replacement Tachometer located in the instrument cluster. You can determine if the sensor is in failure by examining the continuity of the sensor to the tachometer. You can also 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 as pin T26a/12. You should see around 1000 ohms of resistance between these two points. This is a typical part that is found 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.