How to Replace an programming audi key G28 Engine Speed Sensor

Charles the Humble Technician teaches you how to replace the G28 Engine Speed Sensor. This sensor is situated on the outside of the transmission over the flywheel gear. It sends a message to the ECU through the grey wire T55/49 and then to the tachometer located on the instrument cluster.

1. Engine Speed Sensor

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

The sensor is used as a reference to correlate with 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 according to the situation.

If this sensor fails the ECU will display an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are out of sync and possibly indicating the chain stretching or a jump link on the upper timing chain. The code won't appear without the additional information provided by other sensors (G4 or G40).

It's a bit tricky to test because there are various pins on the connector and they all have different functions. The best method for doing this is to measure the resistance between the ECU and the sensor. If the sensor is functional, it should read about 1000 ohms. If you are having problems with this component, look for signs of coolant or oil in the connector bay.

2. Injectors

Yesterday, while accelerating from the highway paytoll at full speed I noticed a significant drop in power. It was like the engine had run out of gas. Or my injectors weren't firing. I took out the spark plugs this morning and found that 3 were soaked in gasoline, and the fourth was dry. When i crank the engine, there are no sparks, i place a tissue on the top of each of the injector holes and the 3 that were drenched in gazoline leap out, however the 4th stays closed. I checked the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I got 0ohm. So i assume the problem is somewhere else.

I also tried to reset the PID but with no luck. The car can start if the G28 is unplugged and is running fine when it is plugged in, but still has intermittent misfire issues at higher RPM. The coolant sensor (G62) even when it is unplugged, shows an ice temperature of -49c. I also noticed that the oil gauge in the cockpit shows 2 bar but the actual pressure is 0.

I'm not certain what to do, but i feel i have pretty much ruled out everything else. But i'm worried that I might have missed something. If anyone has suggestions, please chime in! TIA!

3. Fuel Pump

The fuel pump in the g28 receives signals from the RPM sensor. The GM-style transmitter 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 wrecking yard or in a local parts store. It is simple to test them - simply switch your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump at the connector end facing up). They should be infinite Ohms.

4. ECU

The ECU in our 20vt turbo (3B AAN ABY ADU) engines requires to know the speed and position of the crankshaft in order to make a decision about fuel injector timing, etc. 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 which could cause engine shut down.

A malfunctioning G28 sensor could cause an inaccurate speed counter for the gearbox or a gearbox that shifts faster than normal, and/or a misfire in the gear. It is likely that your sensor is failing and needs to be replaced if you experience any of these symptoms. The good news is they are quite affordable and easy to find particularly when you're looking at the Bosch unit which is what ours are. Alternately, GM's version this part would be an option.

5. Tachometer

A malfunctioning engine speed sensor could be the reason behind numerous problems in your vehicle. It's a crucial component of the transmission in your audi tt key programming, as it transmits information to the ECU on how fast or slowly the engine of the car is turning. This sensor could cause the transmission to malfunction and other components in the car to be affected.

The G5 engine speed sensor is located at the outside of the transmission, above the flywheel ring gear and audi spare Keys sends a signal to the ECU at pin T55/49 through an uncolored wire. The ECU is then able to process this signal to control fuel, timig and boost, and also transmitting it to the G5 Tachometer located in the instrument cluster. You can test for sensor failure by checking 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 and pin T26a/12. There should be the resistance to be around 1000 ohms between these points. This part is common across the audi replacement key a3 key fob replacement audi key fob - continue reading this.., 80-100-200-RS2 series, starting from the 1985 MC all the way up to the 1997 UrS AN and the 1995 RS2 DU, so you might find good ones in wrecking yards.