How to Replace an audi car Key cover G28 Engine Speed Sensor

In this video Charles the Humble Mechanic demonstrates how to replace the G28 engine speed sensor. This sensor is located near the transmission's edge just above the flywheel gear. It sends a signal to the ECU via the grey wire (T55/49), then to the tachometer located in the instrument cluster.

1. Engine Speed Sensor

The sensor is located at the edge of the transmission above the flywheel ring gear, the G28 Engine Speed Sensor sends an electrical signal to ECU pin T55/49 through an uncolored wire. The ECU utilizes this information to control fuel and boost. It also sends an indication to the G5 Tachometer in instrument cluster.

The sensor is used to connect the G40 Camshaft position Sensor. The ecu must be aware of when the crankshaft has reached TDC and also the location of the camshaft in order to activate the spark and injectors.

If this sensor fails, the ECU will display a P00160 code which means the Crank Shaft and Intake Camshaft are not in sync, possibly indicating chain stretch or a jumped link on the upper chain of timing. The code won't appear without the additional information provided by other sensors (G4 or G40).

It can be a bit difficult to test since there are different connector pins, and each one has different functions. The most effective method to test it is to measure the resistance between the ECU and the sensor. It should read about 1000 ohms when the sensor is at full operation. Check for evidence of coolant or oil in the connector bay if you have issues with this part.

2. Injectors

Yesterday, while accelerating from the highway paytoll at a high speed, i noticed a huge decrease in power. It was as if the engine had run out of gas. Or, my injectors were not firing. Today, i pulled out the spark plugs. Three were drenched in gazoline, the fourth one was dry. I put a piece of tissue over each injector hole, and when i turn the engine on without sparks, the three with gazoline jump out. The 4th one remains shut. I inspected the ground connection on ECU pins 14/55, 30/55 and 48/55. i get zero Ohm. So i assume the problem is elsewhere.

I also tried to reset PID without success. The car will start when the G28 is unplugged, and it works fine when the G28 plugged in. However the intermittent misfire issue continues to occur at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature of -49c, even if I unplug it. I also noticed that the oil gauge in the cockpit shows 2 bar while the actual pressure is 0.

I'm not sure what to do, as i think i've pretty much eliminated everything else. But i'm worried that I may have missed something. Please let me know If you have any suggestions! 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 simple to test them - put your DMM in resistance mode and measure between pins 1 (with the bump on the connector's end up) and 2 (2nd from the left on the black connector's end). They must 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 in order to make a decision about timing of fuel injectors, etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If either of these go badly, [Redirect Only] you will see codes on the diagnostic scanner that can cause the engine to shut down.

Some of the signs of a malfunctioning G28 sensor include an inaccurate rev counter in the gearbox, gears shifting quicker than normal and/or a misfire when you're in gear. If you are experiencing any of these issues it is likely your sensor is failing and needs replacing. The good thing is that they are very affordable and easily accessible particularly if you're looking at a Bosch unit which is what ours are. Alternatively, the GM version of this part is also a good option.

5. Tachometer

A failing engine speed sensor could be a cause for a slew of issues with your vehicle. It's a crucial component of the transmission of your audi spare key cost because it relays information to the ECU about how fast or slow the engine of the car is spinning. This sensor Audi Keys Replacement Cost can cause the transmission to fail and other components of the car to be affected.

The G5 engine sensor is located at the outskirts of the transmission, just above the flywheel ring. It sends signals via gray wire to ECU pin T55/49. The ECU uses this signal to regulate fuel and boost, and also to timigrate. It also relays it to the G5 Tachometer inside the instrument cluster. You can test for sensor failure by examining the continuity of the sensor to the tachometer. You can also check continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]) and between pin T6a/1 and pin T26a/12. It should show approximately 1000 ohms of resistance between those two pins. This is the same across the audi car key replacement 80-100-200-RS2 series, starting from the 1985 MC all the way up to the 1997 UrS AN and the 1995 RS2 Du You may also find some good ones in wrecking yards.