How to Replace an audi keyless go G28 Engine Speed Sensor

In this video Charles the humble mechanic demonstrates how to replace the G28 engine speed sensor. The sensor is situated at the top of the transmission, above the flywheel ring gear. It sends a message to the ECU via a grey wire T55/49, then to the tachometer in 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 an electrical signal to ECU pin T55/49 through the grey wire. The ECU then uses this information to control fuel, timig and boost. It also sends a signal to the G5 tachometer inside the instrument cluster.

The sensor is used to connect with the G40 Camshaft position Sensor. The ecu must be aware when the crankshaft is TDC and where the camshaft is located so that it can trigger spark and injectors accordingly.

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

Testing is a bit tricky because there are two pins for the connector and they perform different functions but the most effective way to test it is to measure resistance between the sensor and the ECU. It should read around 1000 ohms when it is at full operation. Examine for evidence of coolant or oil in the connector bay if you are experiencing issues with this component.

2. Injectors

Yesterday, while accelerating at full speed from the highway paytoll, i experienced massive power loss like the engine is out of gas or the injectors are not firing anymore. I pulled out the spark plugs this morning, 3 were soaked in gasoline, and the fourth was dry. I placed a tissue over each hole in the injector and when I start the engine with no sparks, the three that have gazoline pop right out. The 4th one stays closed. I tested the ground connection on ECU pins 14/55, 30/55 and 48/55. I got zero Ohm. I assume that the problem is elsewhere.

I also tried to reset the PID with no success. The car will start when the G28 is disconnected, but it works fine when the G28 connected. However the intermittent misfire issue continues to occur at higher RPM. The coolant sensor (G62), even when it is unplugged, shows a temperature of -49c. Also, i noticed that the gauge for oil pressure in the cockpit is showing 2 bar when the actual pressure is 0.0 if i crank up the engine.

I'm not sure what to do, as i believe that i've completely ruled out all other possibilities. 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 is activated by a signal 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 an extra in a wrecking shop or parts store. Testing them is easy to do - just put your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector's side up) and 2 (2nd from left on the black connector's end). They should be infinite Ohms.

4. ECU

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

A failing G28 sensor could cause an inaccurate speed counter for the gearbox and a gearbox which shifts faster than normal, or a misfire while in gear. If you have any of these problems, it is likely that your sensor is deteriorating and requires replacement audi car key. The good news is they are very cheap and easily accessible, especially in the case of an Bosch unit which is what ours are. Alternatively, GM's version of this part is an excellent choice.

5. Tachometer

A malfunctioning engine sensor can cause a myriad of issues in your vehicle. It is an important part of the transmission in your audi spare key replacement, as it transmits information to the ECU on how fast or slowly the engine is turning. If the sensor fails, it could cause problems for the transmission and the other car's components.

The G5 engine speed sensor is located on the outside of the transmission, above the flywheel ring gear and sends a signal directly to the ECU at pin T55/49 through a grey wire. The ECU is then able to process this signal to regulate fuel, timig and boost, and also sends it on to the G5 Tachometer located in the instrument cluster. You can test for sensor failure by examining the continuity from the sensor to the tachometer. Also, you can 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 and pin T26a/12. You should see approximately 1000 ohms resistance between these two points. This part is common across the audi tt key case audi keys replacement key service (Going In this article) 80-100-200-RS2 series, starting from the 1985 MC all the way up to the 1997 UrS AN and 1995 RS2 DU You may also find them in wrecking yards.