Why Nobody Cares About Audi G28
Why Nobody Cares About Audi G28
Blog Article
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. This sensor is located on the edge of the transmission just above the flywheel ring gear. It transmits a signal to the ECU via a grey wire (T55/49) and then to the tachometer within 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 a signal via the grey wire to pin T55/49. The ECU uses this information to regulate the amount of fuel and boost. It also sends an alert to the G5 Tachometer in instrument cluster.
The sensor is used as a reference for comparing with the G40 Camshaft Position Sensor. The ecu needs to know when the crankshaft has reached TDC and also the location 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 not in alignment with the Intake Camshaft. It could also indicate the possibility of a chain stretch or jumpy chain link in the upper timing chain. The code won't 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 has its own functions. The most effective method to test it is to measure the resistance between the ECU and the sensor. It should read around 1000 ohms if the sensor is in full operation. If you're experiencing issues with this sensor, look for signs 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 massive decrease in power. It was as if the engine was running out of gas. Or, my injectors weren't firing. Today, i pulled out the spark plugs, three were drenched in gazoline, the fourth was dry. When i crank the engine, there are no sparks, I put a piece of tissue on the top of each hole in the injector and the 3 drenched with gazoline pop out, but the 4th stays closed. I inspected the ground connection on ECU pins 14/55,30/55 and 48/55 i get zero ohm. I assume that the problem is in another location.
I also tried to reset the PID with no success. The car will start when the G28 is unplugged, and it runs fine with the G28 connected. However, the intermittent misfire problem here persists at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature value of -49c, even if I unplug it. 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, i feel get more info i have pretty much completely ruled out all other possibilities. However, i'm afraid that I might have missed something. Please let me know should you have any suggestions! TIA!
3. Fuel Pump
The fuel pump of the g28 receives signals from the RPM sensor. The GM-style transmitter is similar to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. You can easily locate the spare in a salvage shop more info 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 end up) and 2 (2nd from left on the black end of the connector). They must be infinite Ohms.
4. ECU
The ECU of our 20vt turbo (3B AAN ABY) engines must be aware of the position and speed of the crankshaft to determine fuel injector timing, etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If you are experiencing issues with either of these sensors, the diagnostic scanner will display codes that could lead to the engine shutting down.
Some of the symptoms of a failing G28 sensor include an inaccurate rev counter in the gearbox and gears that shift faster than normal and/or misfiring when you are in gear. If you have any of these problems, it is likely your sensor is failing and should be replaced. They're cheap and easy to find, especially 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 failing engine sensor could cause a number of problems in your vehicle. It's a vital component of your Audi's transmission, as it sends information to the ECU about how fast or slow the car's crankshaft is turning. This sensor could cause the transmission to malfunction and other car components to be affected.
The G5 engine speed get more info sensor is situated on the outside of the transmission, above the flywheel ring gear and sends a signal to the ECU at pin T55/49 via a grey wire. The ECU uses this signal to control fuel and boost, and also timig. It also relays it to the G5 Tachometer located in the instrument cluster. You can check the sensor for failure by examining the continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. There should be a resistance of approximately 1000 ohms between these points. This is a common feature across the Audi 80-100-200-RS2 series, starting from the 1985 MC up to here the 1997 UrS An and 1995 RS2 Du, so you might find some good ones in wrecking yards.