How to Replace an Audi Replacement 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 located on the edge of the transmission just above the flywheel ring gear. It sends a signal to the ECU via the grey wire (T55/49) and then to the tachometer in the instrument cluster.

1. Engine Speed Sensor

The grey wire is situated at the edges of the transmission, above the flywheel ring. The sensor transmits signals 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 within the instrument cluster.

The sensor is used as a reference for comparing with the G40 Camshaft Position Sensor. The ecu must be aware of when the crankshaft has reached TDC, and the position of the camshaft, so that it can activate the spark and injectors.

If this sensor fails when it fails, the ECU will display an error code P00160. This indicates that the Crank Shaft is out of line with the Intake Camshaft. It could also be a sign of a chain stretch or a jumpy chain link in the upper chain. However, the error code won't appear on its own without additional information from other sensors (G4 and G40).

It can be a bit difficult 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 operational, it should be reading approximately 1000 ohms. If you're having issues with this sensor, look for evidence of coolant or oil in the connector bay.

2. Injectors

Yesterday, as i was accelerating off the highway paytoll at a high speed I noticed a significant drop in power. It was as if the engine had run out of gas. Or, my injectors weren't firing. Today, i pulled out the spark plugs, 3 were drenched with gazoline the 4th one was dry. I placed a tissue over each injector hole and when I start the engine with no sparks, the three that have gazoline pop right out. The 4th one stays shut. I checked the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ i get zero Ohm. I assume that the problem is elsewhere.

I also tried to reset the PID but without success. The car will start when the G28 is unplugged, and it is running fine with the G28 connected. However, the intermittent misfire problem persists at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature value of that is -49c even after unplugging it. I also noticed that the oil gauge in the cockpit shows 2 bars while the actual pressure is zero.

I'm not sure what to do, i think i've pretty much ruled out everything else. However, i'm afraid that I might have missed something. If anyone has any ideas please let me know! TIA!

3. Fuel Pump

The fuel pump in the g28 can be activated by 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 find a spare in a wrecking shop or parts store. It is easy to test them - just switch your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump at the connector's end facing upwards). They should be infinite Ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY, and ADU) engines are equipped with an ECU that must know the position and speed of the crankshaft to make decisions about timing of the fuel injector, for example. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these sensors go badly, you will see codes on the diagnostic scanner which could cause engine shut down.

Some of the symptoms of a failing G28 sensor include an inaccurate gearbox rev counter and gears that shift faster than normal and/or a misfire when you're in gear. If you have any of these issues, it is most likely that your sensor is deteriorating and needs replacing. The good thing is that they are very cheap and easy to find, especially when you're looking at an Bosch sensor, like ours. Alternately, the GM version of this part is also a good option.

5. Tachometer

A damaged engine sensor could cause a myriad of issues within your vehicle. It's an essential component of your audi a1 key's transmission, as it sends information to the ECU about how the replacement audi car key's crankshaft is turning. This sensor could cause the transmission to malfunction and audi Replacement key cost Uk other components in the car to be affected.

The G5 engine sensor is located at the edge of the transmission, over the flywheel ring. It transmits an electrical signal through gray wire to ECU pin T55/49. The ECU utilizes this signal to regulate the flow of fuel and boost and also timig. It also sends it to the G5 Tachometer in instrument cluster. You can check for sensor 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 [79trace [79]) and between pin T6a/1 as well as pin T26a/12. You should detect an average resistance of 1000 ohms between these two points. This is a common feature across the audi keys replacement 80-100-200-RS2 range, beginning with the 1985 MC and up to the 1997 UrS An and 1995 RS2 Du You may also find them in wrecking yards.