How to Replace an audi key fob replacement cost G28 Engine Speed Sensor

In this video, Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. The sensor is located near the edges of the transmission, above the flywheel ring gear. It transmits a signal the ECU via the grey wire (T55/49) which is then sent to the tachometer within the instrument cluster.

1. Engine Speed Sensor

Located on 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 utilizes this information to control boost and fuel. It also sends an indicator to the G5 Tachometer within the instrument cluster.

The sensor is used as a reference point to connect with the G40 Camshaft Position Sensor. The ecu needs to know when the crankshaft is TDC and the location of the camshaft so it can activate 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, possibly indicating chain stretch or cost a jumped link on the upper timing chain. However the code will not appear on its own without additional information from other sensors (G4 and G40).

It's a bit tricky to test because there are various pins on the connector, and each one has different functions. The most effective method to test it is to measure the resistance between the ECU and the sensor. If the sensor is functional, it should read around 1000 ohms. If you are having problems with this sensor, look for signs of coolant or oil in the connector bay.

2. Injectors

Yesterday, as i was accelerating off the highway paytoll at maximum speed I noticed a massive reduction in power. It was like the engine was running out of gas. Or my injectors were not firing. I took out the spark plugs this morning, 3 were soaked in gasoline, and the 4th was dry. I put a piece of tissue over each injector hole and when i start the engine with no sparks, the three with gazoline jump right out. The fourth one remains closed. I inspected the ground connection on ECU pins 14/55,30/55 and 48/55 I got zero ohm. I think the issue is elsewhere.

I also tried to reset the PID with no success. The car is able to start when the G28 is unplugged and is running fine when it is plugged in, but still has the intermittent misfire issue at higher RPM. The coolant sensor (G62) even when it is unplugged, shows an ice temperature of -49c. I also noticed that the oil pressure gauge in the cockpit shows 2 bar while the actual pressure is 0.0 if i crank up the engine.

I don't know what to do. I feel like i've pretty much eliminated everything else. I'm worried that i might have missed something. Please let me know should you have any suggestions! TIA!

3. Fuel Pump

The fuel pump of the g28 gets 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. It is easy to find an extra in a wrecking shop or parts store. It is simple to test them: simply put your DMM into resistance mode and test the distance between pins 1 and 2 (with the bump at the connector's end facing upwards). They should be infinite Ohms.

4. ECU

The ECU of our 20vt turbo (3B AAN ABY ADU) engines needs to know both the position and speed of the crankshaft to make decisions regarding timing of fuel injectors, etc. To accomplish this, it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you have a problem with either of these, the diagnostic scanner will show codes that could cause an engine shut down.

Some of the symptoms of a failed G28 sensor are an inaccurate rev counter in the gearbox and gears that shift faster than normal and/or a misfire when you are in gear. It is probable that the sensor is failing and needs to be replaced if you experience any of these symptoms. The good news is they are quite affordable and easily accessible, especially if you're looking at the Bosch sensor, which is what ours are. Alternatively, the GM version of this unit is also a good option.

5. Tachometer

A malfunctioning engine sensor can cause a myriad of issues in your car. It's a vital component of the audi replacement key cost's transmission since it relays information to the ECU about how fast or slow the car's crankshaft is turning. If this sensor fails, it will affect the performance of the transmission as well as the other car's components.

The G5 engine speed sensor is situated on the edge of the transmission just above the flywheel ring gear. It sends a signal to the ECU at pin T55/49, via an uncolored wire. The ECU uses this signal to control fuel and boost, and also timig. It also transmits it to the G5 Tachometer inside the instrument cluster. You can test the sensor for failure by checking continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection on pin T6a/1 (trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. You should see an average resistance of 1000 ohms between these two points. This is a common component across the audi tt key fob 80 100, 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU. Good ones could be available in wrecking yards.