The Three Greatest Moments In Audi G28 History
How to Replace an audi key programming tt audi key fob fob (articlescad.com) G28 Engine Speed Sensor
Charles the Humble Technician shows you how to replace the G28 Engine Speed Sensor. The sensor is situated near the edges 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
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 a grey wire. The ECU then utilizes this information to regulate the flow of fuel, timig and boost. It also sends an indicator to the G5 Tachometer within the instrument cluster.
The sensor is used to link the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft reached TDC, and the location of the camshaft to trigger the spark and injectors.
If this sensor fails, the ECU will throw an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are not in 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 can be a bit difficult to test because there are various 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. When the sensor is fully operational, it should read about 1000 ohms. Examine for evidence of coolant or oil in the connector bay if you have issues with this part.
2. Injectors
Yesterday, when accelerating from highway paytoll at a high speed I noticed a significant decrease in power. It was as if the engine was running 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. I placed a tissue over each injector hole, and when i turn the engine on without sparks, the three with gazoline jump right out. The 4th one remains closed. I checked the ground connection of ECU pins 14,30, and 48/55. I got zero ohm. I'm assuming that the issue is in another location.
I also tried to reset the PID with no success. The car is able to start when the G28 is not plugged in and is running fine when it is plugged in however it has intermittent misfire issues at higher RPM. The temperature sensor for the 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 bar but the actual pressure is zero.
I'm not sure what to do, as i believe that i've ruled out everything else. But i am afraid I might have missed something. If anyone has any suggestions, please let me know! TIA!
3. Fuel Pump
The fuel pump on the g28 is activated by a signal 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. It is easy to find a spare in a wrecking shop or a parts store. It is easy to test them - just switch your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump at the connector's end facing upwards). They must be infinite Ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY) engines requires to know the position and speed the crankshaft to determine timing of the fuel injector, etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If you have a problem with either one of these, the diagnostic scanner will display the codes that could trigger an engine shut down.
Some of the symptoms of a failed G28 sensor include an inaccurate gearbox rev counter the gears are shifting faster than normal, and/or a misfire when in gear. It is probable that the sensor is failing and requires to be replaced if you encounter any of these symptoms. They're inexpensive and easy to locate particularly if they're an Bosch unit like ours. If you prefer, GM's version of this part would be an option.
5. Tachometer
A malfunctioning engine speed sensor could be the reason behind many issues with your vehicle. It is a crucial part of the audi keyless go's transmission since it relays information to the ECU about how fast or slow the car's crankshaft is rotating. If the sensor fails, it will disrupt the performance of the transmission as well as the other car's components.
The G5 engine sensor is located near the edge of transmission, above the flywheel ring. It transmits a signal via a gray wire to the ECU pin T55/49. The ECU uses this signal to control the amount of fuel and boost, and also to timigrate. It also transmits it to the G5 Tachometer inside the instrument cluster. You can check the sensor for any failure by checking the continuity between it and the tachometer, between ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. There should be an average resistance of 1000 ohms between these points. This is the same across the new audi key 80-100-200-RS2 model, ranging from the 1985 MC all the way up to the 1997 UrS AN and the 1995 RS2 DU So, you may find some good ones in wrecking yards.
