How to Replace an Audi G28 Engine Speed Sensor
In this video Charles the humble mechanic demonstrates how to replace the G28 engine speed sensor. The sensor is located at the edge of transmission just above the flywheel 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
The grey wire is located at the edges of the transmission, above the flywheel ring. The sensor transmits an electrical signal through the grey wire to pin T55/49. The ECU utilizes this information to regulate boost and fuel. It also sends an indicator to the G5 Tachometer within the instrument cluster.
The sensor is used to connect the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft reached TDC, and where the camshaft lies in order to 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 alignment with the Intake Camshaft. It could also be a sign of a chain stretch or a jumpy chain link in the upper timing chain. The code won't show without the additional information provided by other sensors (G4 or G40).
It is a little tricky to test because there are different pins on the connector and they all have 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 around 1000 ohms. Look for signs of coolant, or oil in the connector bay if there are problems with this part.
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 injectors are not firing anymore. I took out the spark plugs this morning and found that 3 were drenched in gasoline and the fourth was dry. I put tissue over each injector hole, and when I start the engine without sparks, the 3 with gazoline jump 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 get 0ohm. I'm assuming that the issue is somewhere else.
I also tried to reset the PID without success. The car will start when the G28 is disconnected, but it works fine when the G28 plugged in. However, the intermittent misfire problem continues to occur at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature of -49c even when i unplug it. I also noticed that the oil gauge in the cockpit shows 2 bars when the actual pressure is zero.
I'm not sure what to do, but i believe that i've eliminated everything else. However, i'm afraid that i might have missed something. Let me know if you have any ideas! TIA!
3. Fuel Pump
The fuel pump of the g28 gets a signal from the RPM sensor. The GM-style sender is the same as the G4 and they both work in the 80 100, 200, UrS and RS2 cars which is why you can easily locate one at a wrecking yard read more or in a local parts store. It is easy to test them: simply switch your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump on the connector's edge facing up). They must be infinite Ohms.
4. ECU
The ECU of our 20vt turbo (3B AAN ABY ADU) engines must be aware of the position and speed of the crankshaft to determine fuel injector timing, etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish replace audi key this. If you encounter a problem with either one of these, the diagnostic scanner will show codes that could lead to an engine shutdown.
Some of the signs of a failed G28 sensor are an inaccurate rev counter for the gearbox the gears are shifting faster than normal and/or misfiring when you're in gear. If you are experiencing any of these problems, it is likely that your sensor click here is failing and requires replacement. The good news is that they are very cheap and easily accessible, especially if you're click here looking at a Bosch sensor, which is what we have. You can also choose the GM version of this component is also a great option.
5. Tachometer
A malfunctioning engine speed sensor could be the cause of many issues with your vehicle. It's a crucial component of the transmission of your Audi, as it here transmits information to the ECU regarding how fast or slowly the car's engine is turning. This sensor can cause the transmission to fail and other components of the car to be affected.
The G5 engine sensor is located near the edge of the transmission, just above the flywheel ring. It transmits an electrical signal through a gray wire to the ECU pin T55/49. The ECU uses this signal to control fuel and boost, and also to timigrate. It also relays it to the G5 Tachometer in instrument cluster. You can check for sensor failure by examining the continuity of the sensor to the tachometer. Additionally, you can 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. There should be the resistance to be around 1000 ohms in these areas. This is the same across the Audi 80-100-200-RS2 model, ranging from the 1985 MC up to the 1997 UrS AN and 1995 RS2 DU You may also find them in wrecking yards.