How to Replace an audi connect key G28 Engine Speed Sensor

In this video Charles the humble mechanic demonstrates how to replace the G28 engine speed sensor. This sensor is located on the edge of the transmission just above the flywheel ring gear. It transmits a signal the ECU via an uncolored wire (T55/49) and then to the tachometer located in 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 the flow of fuel, timig and boost. It also sends an indication to the G5 tachometer in the instrument cluster.

The sensor is used to link the G40 Camshaft position Sensor. The ecu must be aware 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 show a P00160 code which means the Crank Shaft and Intake Camshaft are not in sync, possibly indicating the chain is stretched or a jump link on the upper chain of timing. The code won't appear without the additional information provided by other sensors (G4 or G40).

It can be a bit difficult to test because there are different connector pins, and each one has different functions. The best method for doing this is to measure the resistance between the ECU and the sensor. It should read around 1000 ohms when the sensor is in full operation. Check for signs of coolant, or oil in the connector bay if you are experiencing problems 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 was running out of gas. Or, my injectors weren't firing. I took out the spark plugs this morning, three were soaked with gasoline and the 4th was dry. I put tissue over each hole in the injector and when I start the engine with no sparks, the ones that have gazoline pop right out. The fourth one remains closed. I tested the ground connection of ECU pins 14,30, and 48/55. I got zero ohm. So i assume the problem is in another place.

I also tried to reset the PID with no success. The car will start when the G28 is disconnected and runs fine when it is connected however it is experiencing intermittent misfires at higher RPM. The coolant sensor (G62) even if it is not plugged in, shows an ice temperature of -49c. Also, i noticed that the gauge for oil pressure 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, but i feel i have pretty much eliminated everything else. I'm concerned that i may have missed something. If anyone has any ideas please let me know! TIA!

3. Fuel Pump

The fuel pump in the g28 receives a signal from the RPM sensor. The GM-style transmitter functions similarly to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. You can easily locate the spare in a salvage shop or parts store. Testing them is easy to do - just put your DMM in resistance mode and measure between pins 1 (with the bump on the connector's end up) and 2 (2nd from the left on the black connector's side). They must 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 in order to make a decision about fuel injector timing, etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If either of these goes badly, you will see codes on the diagnostic scanner that can cause the engine to shut down.

Some of the symptoms of a failing G28 sensor include an inaccurate rev counter in the gearbox the gears are shifting faster than normal, and/or a misfire when you're in gear. It is likely that the sensor is failing and requires to be replaced if you encounter any of these signs. They're cheap and easy to find especially if they're an Bosch unit 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 numerous problems in your car. It's an essential component of the audi replacement key cost uk's transmission since it relays information to the ECU about how the car's crankshaft is spinning. If this sensor fails, it could cause problems for the transmission and the other car's components.

The G5 engine sensor is located at the edge of transmission, above the flywheel ring. It sends an electrical signal through an uncolored wire to the ECU pin T55/49. The ECU utilizes this signal to regulate fuel and boost, and also timig. It also relays it to the G5 Tachometer inside the instrument cluster. You can determine if the sensor is in failure by examining the continuity from the sensor to the tachometer. Also, you can check continuity between pin 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 an average resistance of 1000 ohms between these two points. This is a typical part across the audi new key key blade (see it here) 80 100 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU. Good ones could be available in wrecking yards.