How to Replace an audi tt key fob G28 Engine Speed Sensor

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

1. Engine Speed Sensor

It is located on the outside of the transmission, above the flywheel ring gear, the G28 Engine Speed Sensor sends signals to ECU pin T55/49 using an uncolored wire. The ECU utilizes this information to control boost and fuel. It also sends an alert to the G5 Tachometer in instrument cluster.

The sensor serves as a reference for comparing with the G40 Camshaft Position Sensor. The ecu has to be aware of when the crankshaft has reached TDC and also the position of the camshaft, in order to activate the spark and injectors.

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

Testing is a bit challenging as there are two different pins for the connector and they have different functions however the best method to test it is to measure resistance between the sensor and the ECU. It should read about 1000 ohms when the sensor is operating at its maximum. If you are having problems with this part, check for signs of oil or coolant in the connector bay.

2. Injectors

Yesterday, when i was accelerating to the fullest speed from highway paytoll, i experienced a big cut in power like the engine is running out of gas or injectors aren't firing at all. I took out the spark plugs this morning and found that 3 were drenched in gasoline and the fourth was dry. I put a piece of tissue over each injector hole and when I start the engine without sparks, the three that have gazoline pop right out. The 4th one remains closed. I checked the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I got 0ohm. I'm assuming the issue is somewhere else.

I also tried to reset the PID but with no luck. The car will start when the G28 is disconnected and is running fine when it is connected, but still has intermittent misfire issues at higher RPM. The coolant temperature sensor (G62) shows the wrong temperature of -49c even when i unplug it. I also noticed that the oil gauge in the cockpit shows 2 bar when the actual pressure is zero.

I'm not sure what to do. I think I've ruled everything else out. I'm worried that i might have missed something. If anyone has any suggestions, please share them! 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 work 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 take measurements between pins 1 (with the bump on the connector's side up) and 2 (2nd from the left on the black connector's side). They must be infinite Ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY, and audi a3 replacement key a4 replacement key (Yanyiku.cn) ADU) engines are equipped with an ECU that must know the position and speed of the crankshaft in order to make a decision about fuel injector timing etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If you are experiencing issues with either of these, the diagnostic scanner will display codes that could lead to the engine shutting down.

Some of the signs of a failed G28 sensor include an inaccurate gearbox rev counter and gears that shift faster than normal and/or misfiring when you are in gear. It is probable that the sensor is failing and needs to be replaced if you experience any of these signs. They're cheap and easy to find, especially if they're an Bosch model like ours. You can also choose the GM version of this unit is also a good choice.

5. Tachometer

A failing engine speed sensor could be the cause of numerous issues with your vehicle. It's an essential component of your Audi replacement key service's transmission, since it relays information to the ECU about how fast or slow the vehicle's crankshaft 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 on the outside of the transmission, 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 the flow of fuel and boost as well as timig. It also transmits it to the G5 Tachometer in instrument cluster. You can check the sensor for failure by examining the continuity between it and the tachometer. You can also check continuity between ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. It should show around 1000 ohms of resistance between those two pins. This part is common across the replacement audi key cost 80-100-200-RS2 range, from the 1985 MC up to the 1997 UrS AN and the 1995 RS2 Du You may also find them in wrecking yards.