Why People Don t Care About Audi G28
How to Replace an audi spare key G28 Engine Speed Sensor
Charles the Humble Technician teaches how to replace the G28 Engine Speed Sensor. This sensor is situated at the edge of transmission just above the flywheel 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
It is located on the outside of the transmission, above the flywheel ring gear the G28 Engine Speed Sensor sends an electrical signal to ECU pin T55/49 through an uncolored wire. The ECU then uses this information to control fuel, timig and boost. It also sends an indicator to the G5 Tachometer within the instrument cluster.
The sensor serves as a reference for comparing with the G40 Camshaft Position Sensor. The ecu must be aware when the crankshaft is TDC and where the camshaft is located so that it can trigger spark and injectors according to the situation.
If this sensor fails the ECU will display an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are not 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 can be a bit difficult because there are two 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 about 1000 ohms when the sensor is at full operation. Check for signs of coolant, or oil in the connector bay if you are experiencing issues with this component.
2. Injectors
Yesterday, while accelerating from the highway paytoll at a high speed, i noticed a huge decrease in power. It was like the engine was running out of gas. Or my injectors were not firing. In the morning, key i removed the spark plugs, three were drenched with gazoline the fourth was dry. I put a piece of tissue over each injector hole and when I turn the engine on without sparks, the three with gazoline jump out. The 4th one stays shut. I checked the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I get zero Ohm. I'm assuming that the issue is in another location.
I also tried to reset PID without success. The car key cover audi can start when the G28 is not plugged in and runs fine when it is plugged in but it still has the intermittent misfire issue at higher RPM. The coolant temperature sensor (G62) shows the wrong temp value that is -49c even after unplugging it. Also, i noticed that the gauge for oil pressure in the cockpit is showing 2 bar, whereas 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 may have missed something. If anyone has any ideas please share them! TIA!
3. Fuel Pump
The fuel pump in the g28 is activated by a signal by the RPM sensor. The GM-style transmitter is similar to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. It is easy to find a spare in a wrecking shop or parts store. It is simple to test them by putting your DMM in resistance mode and take measurements between pins 1 (with the bump on the connector's side up) and 2 (2nd from the left on the black connector's side). They must be infinite ohms.
4. ECU
The ECU of our 20vt turbo (3B AAN ABY) engines needs to know both the speed and position of the crankshaft in order to make a decision about 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 either of these go wrong, you will receive codes on the diagnostic scanner which can cause the engine to shut down.
A damaged G28 sensor could cause an inaccurate speed counter for the gearbox or a gearbox that shifts faster than normal, or a misfire in gear. If you have any of these issues it is likely that your sensor is going bad and should be replaced. They are cheap and easy-to-find especially in the case of an Bosch model like ours. Alternatively, the GM version of this part is also a good option.
5. Tachometer
A faulty engine speed sensor could be a cause for many problems in your vehicle. It is an important part of the transmission of your Audi Tt Key Fob Not Working because it relays information to the ECU on how fast or slowly the engine is spinning. When this sensor fails, it could disrupt the performance of the transmission and the other car's components.
The G5 engine speed sensor is located on the edge of the transmission above the flywheel ring gear and transmits a signal to the ECU at pin T55/49, via a grey wire. The ECU utilizes this signal to control fuel and boost, as well as timig. It also sends it to the G5 Tachometer located in the instrument cluster. You can determine if the sensor is in failure by examining the continuity from the sensor to the tachometer. Additionally, you can check continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]), and between pin T6a/1 and pin T26a/12. You should see approximately 1000 ohms of resistance between these two points. This is a standard part across the audi key fob 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.