What Do You Think? Heck Is Audi G28?
What Do You Think? Heck Is 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 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 within the instrument cluster.
1. Engine Speed Sensor
It is located on the outside of the transmission, above the flywheel ring gear, the G28 Engine Speed Sensor sends signals to ECU pin T55/49 through the grey wire. The ECU then utilizes this information to regulate the flow of fuel, timig and boost. It also sends an alert to the G5 Tachometer within the instrument cluster.
The sensor serves as a reference point to connect with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft has reached TDC and also the location of the camshaft to trigger the spark and injectors.
If this sensor fails the ECU will throw the P00160 error, which means the Crank Shaft and Intake Camshaft are out of sync, possibly indicating chain stretch or a jumped link on the upper chain of timing. However, the code won't appear on its own without additional information from other sensors (G4 and G40).
It is a little tricky to test since there are different pins on the connector and each one has different functions. The best method for doing this is by measuring the resistance between the ECU and the sensor. If the sensor is functional, it should read about 1000 ohms. Look for signs of coolant or oil in the connector bay if you have issues with this part.
2. Injectors
Yesterday, as i was accelerating off the highway paytoll at a high speed, i noticed a huge reduction in power. It was like the engine had run out of gas. Or my injectors weren't firing. This morning i pull out the spark plugs, three were soaked with gazoline and the fourth one was dry. When I crank the engine without sparks, I put a piece of tissue on top of each injector hole and the 3 drenched with gazoline pop out, but the 4th one stays closed. I inspected the ground connection on ECU pins 14/55, 30/55 and 48/55. i get zero Ohm. I'm assuming that the issue is somewhere else.
I also tried to reset the PID without success. The car can start when the G28 is disconnected and is running fine when it is plugged in however it has intermittent misfire issues at higher RPM. The temperature sensor for coolant (G62) shows the wrong temp value -49c, even if audi a4 spare key I unplug it. Also i noticed that the gauge for oil pressure in the cockpit is showing 2 bar while the actual pressure is 0.0 when i rev the engine.
I'm not sure what to do. I think I've eliminated everything else. But i am afraid i might have missed something. If anyone has suggestions, please let me know! TIA!
3. Fuel Pump
The fuel pump of the g28 receives a signal from the RPM sensor. The GM-style sensor is identical to the G4 and both are used 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. It is easy to test them - just put your DMM into resistance mode and test the distance between pins 1 and 2 (with the bump on the connector's edge facing upwards). They must be infinite Ohms.
4. ECU
The ECU of our 20vt turbo (3B AAN ABY ADU) engines needs to be aware of the position and speed of the crankshaft in order to make a decision about fuel injector timing, etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you encounter a problem with either of these sensors, the diagnostic scanner will display codes that could cause an engine shut down.
Some of the symptoms of a failed G28 sensor are an inaccurate gearbox rev counter, gears shifting quicker than normal and/or misfiring when you're in gear. If you have any of these issues, it is most likely that your sensor is failing and should be replaced. The good news is that they are very cheap and easy to find, especially in the case of an Bosch unit like ours. Alternately, the GM version of this part is also a good read more choice.
5. Tachometer
A malfunctioning engine speed sensor could be a cause for many problems in your vehicle. It's a crucial component of the transmission of your Audi, as it transmits information to the ECU about how fast or slowly the engine of the car is spinning. This sensor could cause the transmission more info to malfunction and other components in the car to be affected.
The G5 engine sensor is located at the edge of transmission, above the flywheel ring. It transmits signals via a gray wire to the ECU pin T55/49. The ECU utilizes this signal to regulate the flow of fuel and boost as well as timig. It also website transmits it to the G5 Tachometer located in the instrument cluster. You can test for sensor failure by examining the continuity of the sensor to the tachometer. Also, you can verify continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]), and between pin T6a/1 as well as pin T26a/12. You should observe approximately 1000 ohms resistance between those points. This is a common lost audi key part that is found across the Audi 80 100 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU. Good ones could be available in wrecking yards.