What The Heck What Exactly Is Audi G28
From Shiapedia
How to Replace an audi replacement keys G28 Engine Speed Sensor
Charles the Humble Technician shows you how to replace the G28 Engine Speed Sensor. The sensor is situated at the top of the transmission just above the flywheel ring gear. It sends a signal to the ECU via a grey wire (T55/49) which is then sent to the tachometer in 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 a signal to ECU pin T55/49 via an uncolored wire. The ECU utilizes this information to regulate fuel and boost. It also sends an indicator 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 has to be aware of 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 a P00160 error message. This means that the Crank Shaft is out of sync 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 show without the additional information supplied by other sensors (G4 or G40).
It's a bit tricky to test because there are different pins on the connector and each has its own functions. The best method for doing this is by measuring the resistance between the ECU and the sensor. It should read approximately 1000 ohms if the sensor is at full operation. Look for signs of coolant, or oil in the connector bay if you have issues with this component.
2. Injectors
Yesterday, while accelerating at full speed from the highway paytoll, I experienced a big cut in power like the engine is running out of gas or the injectors aren't firing at all. I pulled out the spark plugs this morning, three were soaked in gasoline, and the 4th was dry. When I crank the engine, there are no sparks i put tissue on the top of each hole in the injector, the 3 drenched with gazoline pop out, but the 4th one stays closed. I tested the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I get zero Ohm. So i assume the problem is in another place.
I also tried to reset the PID but with no luck. The car can start when the G28 is disconnected and is running fine when it is plugged in, but still has intermittent misfire issues at higher RPM. The coolant sensor (G62) even when unplugged, still shows a temperature of -49c. Also i noticed that the oil pressure gauge in the cockpit is showing 2 bar while the actual pressure is 0.0 if i crank up the engine.
I don't know what to do. I feel like i've 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 in the g28 receives signals from the RPM sensor. The GM-style transmitter is identical to the G4 sender and works on the 80,100,200, UrS, and RS2 vehicles. You can easily find an extra in a wrecking shop or parts store. It is simple to test them: simply switch your DMM into resistance mode and test the distance between pins 1 and 2 (with the bump at the connector's end facing upwards). They must be infinite Ohms.
4. ECU
Our 20vt turbo (3B AAN, ABY, and ADU) engines have an ECU that needs to know the position and speed of the crankshaft in order to make a decision about timing of the fuel injectors, etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If you encounter a problem with either of these sensors, the diagnostic scanner will show codes that could cause an engine shut down.
A malfunctioning G28 sensor can cause an inaccurate speed counter for your gearbox or a gearbox that shifts more quickly than normal, or a misfire in the gear. If you are experiencing any of these issues it is likely your sensor is deteriorating and requires replacement. They're cheap and easy to find, especially if they're an Bosch model like ours. Alternatively, GM's version of this part is an excellent choice.
5. Tachometer
A faulty engine speed sensor could be the cause of numerous problems in your car. It is a crucial part of the Audi's transmission as it sends information to the ECU about how fast or slow the vehicle's crankshaft is spinning. If the sensor fails, it could disrupt the performance of the transmission and the rest of the car's components.
The G5 engine sensor is located at the outskirts of the transmission, just above the flywheel ring. It transmits a signal via gray wire to ECU pin T55/49. The ECU utilizes this signal to control the flow of fuel and boost and also to timigrate. It also transmits it to the G5 Tachometer located in the instrument cluster. You can test the sensor for failure by examining the continuity between it and the tachometer. You can also check continuity between ECU pin T55/49 and the instrument cluster connection on pin T6a/1 (trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. You should see approximately 1000 ohms resistance between these two points. This is a typical part across the audi a5 key fob spare key audi cost (by Bookmarklogin) 80, 100 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU. Good parts could be found in wrecking yards.
