25 Surprising Facts About Audi G28

How to Replace an audi Keyless Go 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 transmission's edge, above the flywheel gear. It transmits a signal the ECU via the grey wire (T55/49) which is then sent to the tachometer located in the instrument cluster.

1. Engine Speed Sensor

The sensor is located at the edge of the transmission just above the flywheel ring gear, the G28 Engine Speed Sensor sends a signal to ECU pin T55/49 through an uncolored wire. The ECU then uses this information to control the flow of fuel, timig and boost. It also sends signals to the G5 tachometer inside the instrument cluster.

The sensor is used to link with the G40 Camshaft position Sensor. The ecu must be aware when the crankshaft is TDC and the location of the camshaft so it can trigger spark and injectors in the right way.

If this sensor fails when it fails, the ECU will display a P00160 error code. This indicates that the Crank Shaft is out of sync with the Intake Camshaft. It could also indicate a chain stretch or a jumped chain link in the upper chain. The code will not appear without the additional information supplied by other sensors (G4 or G40).

It is a little tricky to test since there are several pins on the connector and each one has different functions. The best way to do it is to measure the resistance between the ECU and the sensor. When the sensor is fully operational, it should be reading approximately 1000 ohms. Look for evidence of coolant or oil in the connector bay if you are experiencing problems with this part.

2. Injectors

Yesterday, while accelerating at full speed from the highway paytoll, i experienced a big cut in power like the engine is out of gas or injectors are not firing at all. I took out the spark plugs this morning, three were soaked with gasoline and the 4th was dry. I placed a tissue over each injector hole, audi keys replacement cost and when I start the engine with no sparks, the 3 with gazoline jump out. The 4th one remains closed. I tested the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I got zero Ohm. I assume that the problem is somewhere else.

I also tried to reset PID without success. The car key cover audi can start when the G28 is not plugged in and it runs perfectly when it is connected, but still has the intermittent misfire issue at higher RPM. The coolant sensor (G62) even when it is unplugged, shows a temperature of -49c. 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, as i believe that i've eliminated everything else. But 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 can be activated by a signal sent from the RPM sensor. The GM-style transmitter functions similarly to the G4 sender and works on the 80,100,200, UrS, and RS2 vehicles. It is easy to find a spare in a wrecking shop or a parts store. Testing them is easy - 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 end of the connector). They must be infinite Ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY and ADU) engines have an ECU that has to know the position and speed of the crankshaft in order to make a decision about timing of the fuel injectors, etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you encounter a problem with either of these, the diagnostic scanner will show the codes that could trigger an engine shut down.

The signs of a failing G28 sensor are an inaccurate rev counter in the gearbox the gears are shifting faster than normal and/or a misfire when you are in gear. If you have any of these issues, it is most likely that your sensor is deteriorating and requires replacement. They're cheap and easy to find particularly if they're a Bosch sensor like ours. You can also choose the GM version of this unit is also a good option.

5. Tachometer

A faulty engine speed sensor could be the reason behind a slew of issues in your vehicle. It's a crucial component of the transmission in your audi replacement keys, as it transmits information to the ECU about how fast or slowly the engine of the car is turning. This sensor can cause the transmission to fail and other components in the car to be affected.

The G5 engine speed sensor is located at the outside of the transmission just above the flywheel ring gear and transmits a signal to the ECU at pin T55/49 via a grey wire. The ECU utilizes this signal to control the amount of fuel and boost, and also timig. It also transmits it to the G5 Tachometer in instrument cluster. You can determine if the sensor is in failure by examining the continuity from 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 [79]), and between pin T6a/1 and pin T26a/12. You should observe around 1000 ohms of resistance between those points. This is a common feature across the audi replacement key service near me 80-100-200-RS2 range, beginning with the 1985 MC and up to the 1997 UrS AN and the 1995 RS2 DU You may also find them in wrecking yards.