10 Things You Learned In Preschool To Help You Get A Handle On Audi G28

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. This sensor is situated on the outside of the transmission just above the flywheel gear. It transmits a signal to the ECU through an uncolored wire T55/49, then to the tachometer on the instrument cluster.

1. Engine Speed Sensor

The grey wire is located at the edges of the transmission, above the flywheel ring. This sensor sends an electrical signal through the grey wire to pin T55/49. The ECU then uses this information to control fuel, timig and boost. It also sends an alert to the G5 Tachometer within the instrument cluster.

The sensor serves as a reference for comparing with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft is TDC and where the camshaft is so it can activate spark and injectors accordingly.

If this sensor fails to function, the ECU will display an error code P00160. This means that the Crank Shaft is out of line 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. However, the error code won't be displayed on its own without additional information from other sensors (G4 and G40).

It's a bit tricky to test because there are several pins on the connector and they all have different functions. The best way to do it is by measuring the resistance between the ECU and the sensor. It should read around 1000 ohms when the sensor is in full operation. If you're having issues with this component, look for evidence of oil or coolant in the connector bay.

2. Injectors

Yesterday, when accelerating from highway paytoll at a high speed I noticed a significant reduction in power. It was like the engine was running out of gas. Or, my injectors weren't firing. I took out the spark plugs this morning, 3 were drenched in gasoline and the fourth was unclean. When i crank the engine with no sparks i put tissue on the top of each of the injector holes and the 3 drenched with gazoline jump out but the 4th stay closed. I checked the ground connection on ECU pins 14/55, 30/55 and 48/55. I get 0ohm. I'm assuming that the issue is in another location.

I also tried to reset the PID but without success. The car will start when the G28 is disconnected, but it runs fine with the G28 plugged in. However, the intermittent misfire problem still occurs at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temp value -49c, even if I unplug it. I also noticed that the oil pressure gauge in the cockpit shows 2 bar while the actual pressure is 0.0 when I crank up the engine.

I'm not certain what to do, as i feel i have pretty much completely ruled out all other possibilities. But i'm worried that i might have missed something. If anyone has suggestions, please share them! TIA!

3. Fuel Pump

The fuel pump on the g28 is activated by a signal from the RPM sensor. The GM-style sensor is the same as the G4 and both are used in the 80 100 200, UrS and RS2 cars which is why you can easily locate one at a salvage yard or at a parts store. Test them out to do - just put your DMM in resistance mode and measure the resistance between pins 1 (with the audi replacement key bump on the connector's side up) and 2 (2nd from the left on the black connector's end). They should be infinite Ohms.

4. ECU

The ECU in our 20vt turbo (3B AAN ABY ADU) engines requires to be aware of the position and speed of the crankshaft to make decisions regarding timing of the fuel injector, etc. In order to do this it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you encounter a problem with either of these sensors, the diagnostic scanner will display codes that could cause the engine shutting down.

Some of the signs of a failing G28 sensor are an inaccurate rev counter for here the gearbox the gears are shifting faster than normal, and/or a misfire when you're in gear. website It is likely that the sensor is failing and requires to be replaced if you encounter any of these signs. The good news is they are quite affordable and readily available, especially when you're looking at the Bosch unit more info like ours. Alternatively, the GM version of this component is also a good option.

5. Tachometer

A malfunctioning engine speed sensor could be the reason behind a slew of issues in your vehicle. It's an essential component of check here the transmission in your Audi because it relays information to the ECU on how fast or slow the engine is turning. This sensor could cause the transmission to fail and other car components to be affected.

The G5 engine sensor is located near the edge of the transmission, over the flywheel ring. It sends an electrical signal through gray wire to ECU pin T55/49. The ECU then processes this signal to regulate the flow of fuel, timig and boost, and also sends it on to the G5 tachometer inside the instrument cluster. You can check for sensor failure by examining the continuity from 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 until the 1997 UrS AAN and 1995 RS2 ADU. Good ones might be availble in wrecking yards.