What Are The Biggest "Myths" About Audi G28 May Actually Be Right
What Are The Biggest "Myths" About Audi G28 May Actually Be Right
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How to Replace an Audi G28 Engine Speed Sensor
In this video, Charles the humble mechanic demonstrates how to replace the G28 engine speed sensor. The sensor is located on the edge of the transmission just above the flywheel ring gear. It sends a message to the ECU via the grey wire T55/49 and then to the tachometer located on the instrument cluster.
1. Engine Speed Sensor
The grey wire is located on the outside of the transmission, just above the flywheel ring. The sensor sends signals through the grey wire to pin T55/49. The ECU then uses this information to control the boost, fuel, and timig. It also sends an indication to the G5 Tachometer in instrument cluster.
The sensor is used as a reference point to connect with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft is TDC and where the camshaft is located so that it can start spark and injectors in the right way.
If this sensor fails the ECU will display an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are not in sync and could indicate the chain is stretched or a jump link on the upper chain of timing. However the code will not appear on its own, without additional information from other sensors (G4 and G40).
Testing is a bit challenging since there are two connector pins, and they serve different purposes but the most effective method to test it is to measure resistance between the sensor and the ECU. When the sensor is functional, it should read approximately 1000 ohms. Check for signs of coolant, or oil in the connector bay if you are experiencing problems with this part.
2. Injectors
Yesterday, when i was accelerating to the fullest speed from highway paytoll, I experienced a big cut in power as if the engine was running out of gas or the injectors are not firing at all. This morning i pull out the spark plugs. Three were drenched in gazoline, the fourth was dry. I put a piece of tissue over each hole in the injector and when i turn the engine on without sparks, the three with gazoline jump right out. The 4th one stays closed. I tested the ground connection on ECU pins 14/55,30/55 and 48/55 I got 0ohm. I assume that the problem is elsewhere.
I also tried to reset PID without success. The car will start when the G28 is unplugged, and it works fine when the G28 plugged in. However the intermittent misfire issue still occurs at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature value of that is -49c even after unplugging it. I also noticed that the oil gauge in the cockpit shows 2 bar but the actual pressure is zero.
I'm not sure what to do. I think I've eliminated everything else. I'm concerned 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 signals from the RPM sensor. The GM-style sensor is identical to 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 salvage yard or in a local parts store. Test them out by putting your DMM in resistance mode and measure between pins 1 (with the bump on the connector's end up) and 2 (2nd from 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 be aware of the speed and position of the crankshaft in order to make decisions regarding timing of the fuel injector, for example. In order to do this it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these sensors go bad you will get codes on the diagnostic scanner which could cause engine shut down.
A malfunctioning G28 sensor can cause an inaccurate speed counter for your gearbox or a gearbox that shifts faster than normal, or a misfire while in the gear. It is likely that the sensor is failing and requires to be replaced if you experience any of these signs. The good news is they are read more quite affordable and readily available, especially when you're looking at the Bosch unit which is what we have. If you prefer, GM's version of this part is an option.
5. Tachometer
A faulty engine speed sensor could be the reason behind numerous issues in your vehicle. It is an important part of the transmission in your Audi because it relays information to the ECU about how fast or slow the engine is turning. If the sensor fails, it can disrupt the performance of the transmission and the rest of the car's read more components.
The G5 engine speed sensor is located at the outside of the transmission just above the flywheel ring gear. It sends a signal directly to the ECU at pin T55/49, via an uncolored wire. The ECU uses this signal to control fuel and boost, as well as timig. It also sends it to the more info G5 Tachometer in instrument cluster. You can check for sensor failure by examining the continuity from click here the sensor to the tachometer. Also, you can 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. It should show click here approximately 1000 ohms resistance between these two points. This is a standard part that is found 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 parts could be found in wrecking yards.