How to Replace an audi keyfob G28 Engine Speed Sensor

In this video, Charles the humble mechanic demonstrates how to replace the G28 engine speed sensor. This sensor is situated at the edge of transmission just above the flywheel gear. It transmits a signal to the ECU via a grey wire (T55/49) and audi car Keys replacement then to the tachometer within the instrument cluster.

1. Engine Speed Sensor

The grey wire is located at the edges of the transmission, directly above the flywheel ring. The sensor transmits signals through the grey wire to pin T55/49. The ECU uses this information to regulate fuel and boost. It also sends an indicator to the G5 Tachometer in instrument cluster.

The sensor is used to correlate 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 activate spark and injectors according to the situation.

If this sensor fails, the ECU will display a P00160 error message. This means that the Crank Shaft is out of alignment with the Intake Camshaft. It could also be a sign of an issue with the chain or a jumpy chain link in the upper chain. The code won't appear without the additional information supplied by other sensors (G4 or G40).

Testing is a bit tricky as there are two different connector pins and they perform different functions but the most effective way to test it is to measure resistance between the sensor and the ECU. It should read around 1000 ohms if the sensor is at full operation. Look for signs of coolant or oil in the connector bay if there are issues with this part.

2. Injectors

Yesterday, as i was accelerating off the highway paytoll at a high speed I noticed a significant decrease in power. It was like the engine had run out of gas. Or, my injectors weren't firing. Today, i pulled out the spark plugs. Three were drenched with gazoline the fourth one was dry. When i crank the engine without sparks, i place a tissue on the top of each hole in the injector, the 3 drenched with gazoline leap out, however the 4th one stays shut. I inspected the ground connection on ECU pins 14/55,30/55 and 48/55 I get zero ohm. I'm assuming that the issue is somewhere else.

I also tried to reset the PID without success. The car will start when the G28 is disconnected, but it is running fine with the G28 plugged in. However, the intermittent misfire problem still occurs at higher RPM. The coolant sensor (G62) even if it is not plugged in, shows temperatures of -49c. I also noticed that the oil gauge in the cockpit shows 2 bar while the actual pressure is zero.

I don't know what to do. I think I've all other possibilities out. I'm worried that i might have missed something. Let me know should you have any suggestions! TIA!

3. Fuel Pump

The fuel pump in the g28 is activated by a signal sent by the RPM sensor. The GM-style transmitter is identical to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. You can easily find a spare in a wrecking shop or a parts store. It is simple to test them - put your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector end up) and 2 (2nd from left on the black end of the connector). They must be infinite Ohms.

4. ECU

The ECU in our 20vt turbo (3B AAN ABY) engines requires to know the position and audi Car Keys replacement speed the crankshaft to determine timing of fuel injectors, etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If either of these go wrong, you will receive 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 more quickly than normal, or a misfire in gear. It is probable that the sensor is failing and needs to be replaced if you encounter any of these signs. They are cheap and easy-to-find especially in the case of an Bosch sensor like ours. You can also choose the GM version of this part is also a good choice.

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 car keys replacement since it sends information to the ECU about how fast or slow the car's engine is turning. If the sensor fails, it can affect the performance of the transmission, as well as the other car's components.

The G5 engine speed sensor is located 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 then processes this signal to control fuel, timig and boost and then transmitting it to the G5 tachometer in the instrument cluster. You can determine if the sensor is in failure by examining the continuity of 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 detect a resistance of approximately 1000 ohms between these two points. This is a common part that is found across the audi tt key replacement 80, 100, 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU so good ones might be availble in wrecking yards.