Your Worst Nightmare Concerning Audi G28 Get Real
Your Worst Nightmare Concerning Audi G28 Get Real
Blog Article
How to Replace an Audi G28 Engine Speed Sensor
In this video Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. This sensor is located at the top of the transmission above the flywheel ring gear. It sends a signal to the ECU via a grey wire (T55/49) and then to the tachometer located in the instrument cluster.
1. Engine Speed Sensor
Located on the edge of the transmission, above the flywheel ring gear G28 Engine Speed Sensor sends a signal to ECU pin T55/49 via an uncolored wire. 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 serves as a reference to correlate with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft is TDC and where the camshaft is located so that it can trigger spark and injectors accordingly.
If this sensor fails, the ECU will throw an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are out of sync and possibly indicating chain stretch or a jumped link on the upper chain of timing. However the code will not appear on its own without additional information from other sensors (G4 and G40).
Testing is a bit challenging as there are two different pins for the connector and they serve different purposes but the most effective method of testing it is to measure resistance between the sensor and the ECU. When the sensor is functional, it should read approximately 1000 ohms. If you are having problems with this component, look for evidence of oil or coolant in the connector bay.
2. Injectors
Yesterday, when accelerating from highway paytoll at full speed, i noticed a huge reduction 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 place a tissue on top of each injector hole and the 3 drenched with gazoline jump out but the 4th stays shut. I checked the ground connection on ECU pins 14/55,30/55 and 48/55 I got zero Ohm. Therefore, i think the issue is in another place.
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 issue persists at higher RPM. The coolant sensor (G62) even when unplugged, still shows an ice temperature of -49c. I also noticed that the oil gauge in the cockpit shows 2 bar but the actual pressure is zero.
I'm not sure what to do, but i feel i have pretty much completely ruled out all other possibilities. But i am afraid I may have missed something. Let me know if you have any ideas! TIA!
3. Fuel Pump
The fuel audi keys 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 junkyard or from a parts store. Test them out by putting your DMM in resistance mode and measure between pins 1 (with the bump on the connector end up) and 2 (2nd from the left on the black connector's end). They must be infinite Ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY ADU) engines requires to know the position and speed of the crankshaft to determine timing of fuel injectors, etc. To do this, it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you have a problem with either one of these, the diagnostic scanner will display codes that could lead to an engine shut down.
Some advanced key audi of the signs of a failing G28 sensor include an inaccurate rev counter for the gearbox, audi advanced key gears shifting quicker than normal and/or misfiring when you are in gear. It is likely that your sensor is failing and requires to be replaced if you experience any of these symptoms. The good thing is that they are very cheap and easily accessible particularly if you're looking at an Bosch model, which is what ours are. You can also choose the GM version of this unit is also a good choice.
5. Tachometer
A more info damaged engine sensor could cause a number of problems in your vehicle. It's a crucial component of the transmission of your Audi since it sends information to the ECU about how fast or slowly the car's engine is turning. If the sensor fails, it could affect the performance of 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 audi lost key replacement ECU utilizes this signal to control the amount of fuel and boost, and also timig. It also transmits it to the G5 Tachometer located in the instrument cluster. You can test the sensor for any failure by checking the continuity between it and the tachometer, between ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. You should observe around 1000 ohms of resistance between those two pins. This is a typical part across the Audi 80, 100, 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU. Good ones could be available in wrecking yards.