The Most Profound Problems In Audi G28

How to Replace an audi car key Cover G28 Engine Speed Sensor

Charles the Humble Technician teaches how to replace the G28 Engine Speed Sensor. This sensor is situated at the edge of transmission just above the flywheel gear. It sends a signal to the ECU via the grey wire (T55/49), then 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, the G28 Engine Speed Sensor sends signals to ECU pin T55/49 through a grey wire. The ECU uses this information to regulate fuel and boost. It also sends signals to the G5 tachometer in the instrument cluster.

The sensor is used to connect with the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft is TDC and where the camshaft is so it can start spark and injectors according to the situation.

If this sensor fails, the ECU will throw a P00160 code which means 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 won't be displayed on its own without additional information from other sensors (G4 and G40).

Testing is a bit tricky because there are two connector pins, and they perform different functions but the most effective way to test it is to measure resistance between the sensor audi spare Keys and the ECU. When the sensor is operational, it should be reading around 1000 ohms. If you're having issues with this part, check for signs of coolant or oil in the connector bay.

2. Injectors

Yesterday, when accelerating from highway paytoll at full speed I noticed a massive decrease in power. It was as if the engine had run out of gas. Or my injectors were not firing. I took out the spark plugs this morning, 3 were soaked with gasoline and the fourth was unclean. I put tissue over each hole in the injector and when I turn the engine on without sparks, the ones that have gazoline pop right out. The 4th one remains closed. I tried to test the ground connections of ECU pins 14,30 and 48/55. I found zero ohm. I'm assuming the issue is in another place.

I also tried to reset the PID with no success. The car will start when the G28 is disconnected, but it is running fine with the G28 plugged in. However the intermittent misfire issue persists at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature of -49c, even if I unplug it. I also noticed that the oil gauge in the cockpit shows 2 bar while the actual pressure is zero.

I'm not certain what to do, as i feel i have pretty much ruled out 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 receives a signal from the RPM sensor. The GM-style transmitter is identical to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. It is easy to find an extra in a wrecking shop or a parts store. Testing them is easy by putting 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 left on the black connector's side). They must be infinite Ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY, and ADU) engines have an ECU that needs to be aware of the speed and position of the crankshaft in order to make a decision 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 goes badly, you will see codes on the diagnostic scanner that can lead to engine shutdown.

Some of the signs of a failing G28 sensor include an inaccurate gearbox rev counter the gears are shifting faster than normal and/or a misfire when you're in gear. It is likely that the sensor Audi connect key is failing and requires to be replaced if you notice any of these signs. They're cheap and easy to find especially when they're a Bosch sensor like ours. Alternatively, GM's version of this component is an option.

5. Tachometer

A failing engine sensor could cause a myriad of issues in your vehicle. It's a crucial component of the transmission in your audi a3 replacement key since it sends information to the ECU about how fast or slow the engine of the car is turning. If this sensor fails, it could affect the performance of the transmission and the other car's components.

The G5 engine sensor is located near the edge of the transmission, just above the flywheel ring. It transmits a signal via a gray wire to the ECU pin T55/49. The ECU utilizes this signal to regulate the flow of fuel and boost and also timig. It also sends it to the G5 Tachometer located in the instrument cluster. You can test for sensor failure by examining the continuity of the sensor to the tachometer. You can also check continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]) and replace between pin T6a/1 as well as pin T26a/12. You should observe around 1000 ohms of resistance between those points. This part is common across the audi keys 80-100-200-RS2 range, from the 1985 MC up to the 1997 UrS An and 1995 RS2 DU, so you might find good ones in wrecking yards.