Ten Apps To Help Manage Your Audi G28
Ten Apps To Help Manage Your Audi G28
Blog Article
How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. This sensor is located on the outside of the transmission, above the flywheel gear. It sends a signal to the ECU via a grey wire (T55/49) which is then sent to the tachometer within the instrument cluster.
1. Engine Speed Sensor
The grey wire is situated on the outside of the transmission, directly above the flywheel ring. The sensor transmits an electrical signal through the grey wire to pin T55/49. The ECU then utilizes this information to regulate the boost, fuel, and timig. It also sends an alert to the G5 Tachometer in instrument cluster.
The sensor is used as a reference point to connect with the G40 Camshaft Position Sensor. The ecu has to know when the crankshaft reached TDC and also the location of the camshaft in order to activate the spark and injectors.
If this sensor fails the ECU will show an error code P00160 which indicates that the Crank Shaft and Intake Camshaft aren't in sync, possibly indicating the chain stretching or a jump link on the upper chain of timing. The code will not appear without the additional information provided by other sensors (G4 or G40).
Testing is a bit challenging as there are two different connector pins and they serve different purposes however the best way to test it is to measure resistance between the sensor and the ECU. It should read approximately 1000 ohms when it is in full operation. If you're experiencing issues with this part, check for signs of oil or coolant in the connector bay.
2. Injectors
Yesterday, when accelerating from 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. I took out the spark plugs this morning and found that 3 were soaked with gasoline and the fourth was unclean. When I start the engine with no sparks i put tissue on top of each injector hole and the 3 that were drenched in gazoline pop out, but the 4th one stays closed. I checked the ground connection of ECU pins 14,30, and 48/55. I got zero ohm. Therefore, i think the issue is in another place.
I also tried to reset PID without success. The car will start when the G28 is disconnected, but it runs fine with the G28 plugged in. However the intermittent misfire issue persists at higher RPM. The temperature sensor for coolant (G62) shows the wrong temp value that is -49c even after unplugging it. I also noticed that the oil gauge in the cockpit shows 2 bars while the actual pressure is 0.
I'm not certain what to do, but i feel i have pretty much completely ruled out all other possibilities. However, i'm afraid that I may have missed something. Please 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 by the RPM sensor. The GM-style transmitter 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 or at a parts store. It is simple to test them - simply put your DMM into resistance mode and test the distance between pins 1 and 2 (with the bump at the connector end facing up). 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 make decisions regarding fuel injector timing, etc. To do this, it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these here go badly, you will see codes on the diagnostic scanner which can cause the engine to shut down.
Some of the signs of a failed G28 sensor include an inaccurate rev counter for the gearbox and gears that shift faster than normal and/or misfiring when you're in gear. If you are experiencing any of these issues, it is most likely that your sensor is deteriorating and should be replaced. The good news is they are very affordable and readily available particularly when you're looking at an Bosch unit which is what ours are. If you prefer, GM's version of this part would be an option.
5. Tachometer
A malfunctioning engine sensor can cause a myriad of issues within your vehicle. It's an essential component of your Audi's transmission, as it sends information to the ECU about how fast or slow the car's crankshaft is more info spinning. If get more info this sensor fails, it could affect the performance of the transmission as well as the other car's components.
The G5 engine speed sensor is situated on the edge of the transmission just above the flywheel ring gear and sends a signal directly to the ECU at pin T55/49, via a grey wire. The ECU then processes the signal to control the flow of fuel, timig and boost as well as transmitting it to the G5 tachometer inside the instrument cluster. You can determine if the sensor is in failure by examining read more the continuity of 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 [79]), and between pin T6a/1 as well as get more info pin T26a/12. You should see approximately 1000 ohms of resistance between those points. This part is common across the Audi 80-100-200-RS2 series, starting beginning with the 1985 MC and up to the 1997 UrS AN and the 1995 RS2 Du, so you might find good ones in wrecking yards.