10 Things Youll Need To Be Aware Of Audi G28

How to Replace an Audi G28 Engine Speed Sensor
In this video, Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. This sensor is situated on the outside of the transmission, above the flywheel gear. It sends a signal to the ECU via a grey wire (T55/49), then to the tachometer located in the instrument cluster.
1. Engine Speed Sensor
The grey wire is located 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 fuel and boost. It also sends an indication to the G5 tachometer inside the instrument cluster.
The sensor is used to correlate with the G40 Camshaft position Sensor. audi a1 car key to know when the crankshaft reached TDC, and the location of the camshaft to trigger the spark and injectors.
If audi a1 key fails, the ECU will display a P00160 error code. This means that the Crank Shaft is out of alignment with the Intake Camshaft. It could also indicate a chain stretch or a jumped chain link in the upper chain of timing. However, the code won't be displayed on its own without additional information from other sensors (G4 and G40).
It is a little tricky to test as there are different connector pins, and they all have different functions. The best way to do it is to measure the resistance between the ECU and the sensor. It should read approximately 1000 ohms when the sensor 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 a high speed I noticed a massive drop in power. It was like the engine had run out of gas. Or my injectors were not firing. This morning i pull out the spark plugs, three were drenched with gazoline the 4th one was dry. I put tissue over each injector hole, and when I turn the engine on without sparks, the three with gazoline jump right out. The fourth one remains closed. I tested the ground connection on ECU pins 14/55,30/55 and 48/55 I get zero Ohm. Therefore, i think the issue is somewhere else.
I also tried to reset the PID but with no luck. The car will start when the G28 is not plugged in and is running fine when it is plugged in, but still has the intermittent misfire issue at higher RPM. The coolant temperature sensor (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 bar when the actual pressure is zero.
I'm not sure what to do. audi car keys feel like i've pretty much eliminated everything else. I'm concerned that i may have missed something. If anyone has any suggestions, please share them! TIA!
3. Fuel Pump
The fuel pump in the g28 is activated by a signal sent from the RPM sensor. The GM-style sensor is the same as the G4 and both function in the 80 100, 200, UrS and RS2 cars which is why you can easily locate one at a wrecking yard or in a local parts store. It is easy to test them - just switch your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump on the connector's edge facing upwards). 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 to make a decision about timing of the fuel injectors, etc. To accomplish this, it uses a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you encounter a problem with either of these, the diagnostic scanner will display codes that could cause the engine shutting down.
A damaged G28 sensor could cause an inaccurate speed counter for the gearbox and a gearbox which shifts more quickly than normal, and/or a misfire in gear. It is likely that your sensor is failing and requires to be replaced if you notice any of these symptoms. They are cheap and easy-to-find especially when they're an Bosch unit like ours. Alternately, GM's version this part is a good option.
5. Tachometer
A faulty engine speed sensor could be the cause of many problems in your vehicle. It is a crucial part of your Audi's transmission, as it sends information to the ECU about how the car's crankshaft is turning. This sensor could cause the transmission to fail and other components in the car to be affected.
The G5 engine speed sensor is situated on the outside of the transmission above the flywheel ring gear and transmits a signal to the ECU at pin T55/49, via a grey wire. The ECU is then able to process the signal to control fuel, timig, and boost, and also sends it on to the G5 tachometer 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 examine the continuity between pins T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]) and between pin T6a/1 and pin T26a/12. It should show around 1000 ohms of resistance between those points. This is a typical part across the Audi 80, 100 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU, so the best parts could be found in wrecking yards.