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. The sensor is located at the top of the transmission above the flywheel ring gear. It transmits a signal the ECU via the grey wire (T55/49) and
audi key replacement cost then to the tachometer in the instrument cluster.
1. Engine Speed Sensor
Located on the edge of the transmission just above the flywheel ring gear G28 Engine Speed Sensor sends a signal to ECU pin T55/49 using the grey wire. The ECU utilizes this information to regulate fuel and boost. It also sends an indication to the G5 tachometer inside the instrument cluster.
The sensor is used as a reference for comparing with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft is TDC and the location of the camshaft so it can trigger spark and injectors according to the situation.
If this sensor fails when it fails, the ECU will display a P00160 error code. This means that the Crank Shaft is not in sync with the Intake Camshaft. It could also indicate a chain stretch or a jumpy chain link in the upper timing chain. However the code will not appear on its own, without additional information from other sensors (G4 and G40).
Testing can be a bit difficult as there are two different pins for the connector and they perform different functions but the most effective method of testing it is to measure the resistance between the sensor and the ECU. When the sensor is fully operational, it should read about 1000 ohms. If you're having issues with this part, check for signs of coolant or oil in the connector bay.
2. Injectors
Yesterday, as i was accelerating off the highway paytoll at maximum speed, i noticed a huge decrease in power. It was as if the engine had run out of gas. Or, my injectors weren't firing. I pulled out the spark plugs this morning and found that 3 were soaked with gasoline and the fourth was unclean. When I crank the engine, there are no sparks, I put a piece of tissue on the top of each hole in the injector
audi key replacement cost and the 3 that were drenched in gazoline pop out, but the 4th stays closed. I tried to test the ground connections of ECU pins 14,30 and 48/55. I got 0ohm. I think the issue is somewhere else.
I also tried to reset the PID without success. The
replacement car key audi will start if the G28 is not plugged in and runs fine when it is plugged in, but still is experiencing intermittent misfires at higher RPM. The coolant temperature sensor (G62) shows the wrong temperature value of -49c even when i unplug it. I also noticed that the oil gauge in the cockpit shows 2 bars but the actual pressure is 0.
I'm not sure what to do. I think I've all other possibilities out. I'm afraid i may have missed something. Let me know If you have any suggestions! TIA!
3. Fuel Pump
The fuel pump on the g28 is activated by a signal from the RPM sensor. The GM-style sender 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 from a parts store. Test them out to do - just put your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector end up) and 2 (2nd from left on the black end of the connector). They must be infinite ohms.
4. ECU
Our 20vt turbo (3B AAN, ABY and ADU) engines are equipped with an ECU that must be aware of the speed and position of the crankshaft to make decisions about fuel injector timing etc. In order to do this it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you are experiencing issues with either of these sensors, the diagnostic scanner will display codes that could cause an engine shutdown.
A failing G28 sensor could result in an inaccurate speed counter for your gearbox, a gearbox that shifts faster than normal, and/or a misfire while in gear. It is possible that the sensor is failing and requires to be replaced if you encounter any of these symptoms. The good news is that they are quite affordable and easy to find, especially in the case of the Bosch unit which is what ours are. You can also choose the GM version of this unit is also a great option.
5. Tachometer
A faulty engine speed sensor could be the cause of many issues with your vehicle. It's a vital component of the Audi's transmission because it communicates to the ECU about how fast or slow the car's crankshaft is spinning. When this sensor fails, it will affect the performance of the transmission as well as the other car's components.
The G5 engine sensor is located at the outskirts of the transmission, over the flywheel ring. It transmits signals via an uncolored wire to the ECU pin T55/49. The ECU is then able to process this signal to control fuel, timig, and boost, and also transmitting it to the G5 Tachometer located in the instrument cluster. You can determine if the sensor is in failure by checking continuity from the sensor to the tachometer. Additionally, you can examine the continuity between pins T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]), and between pin T6a/1 and pin T26a/12. There should be the resistance to be around 1000 ohms between these points. This is the same across the
audi key replacement cost 80-100-200-RS2 range, from the 1985 MC up to the 1997 UrS AN and the 1995 RS2 Du You may also find them in wrecking yards.