How to Replace an audi replacement key service near me G28 Engine Speed Sensor
In this video, Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. This sensor is located near the transmission's edge, above the flywheel gear. It transmits a signal the ECU via the grey wire (T55/49), then to the tachometer in the instrument cluster.
1. Engine Speed Sensor
The grey wire is situated at the edges of the transmission, just above the flywheel ring. The sensor sends signals through the grey wire to pin T55/49. The ECU then utilizes this information to regulate the flow of fuel, timig and boost. It also sends signals to the G5 tachometer in the instrument cluster.
The sensor is used as a reference point to connect with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft is TDC and where the camshaft is so it can activate spark and injectors according to the situation.
If this sensor fails when it fails, the ECU will display an error code P00160. This indicates that the Crank Shaft is not in sync with the Intake Camshaft. It could also be a sign of the possibility of a chain stretch or jumped chain link in the upper chain. However, the error code won't be displayed 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 way to do it is to measure the resistance between the ECU and the sensor. If the sensor is functional, it should read around 1000 ohms. If you're experiencing issues with this part, check for evidence of oil or coolant in the connector bay.
2. Injectors
Yesterday, when i was accelerating to the fullest speed from highway paytoll, I experienced an abrupt drop in power like the engine is out of gas or the injectors are not firing at all. In the morning, i removed the spark plugs, 3 were drenched in gazoline, the 4th one was dry. When I crank the engine with no sparks i put tissue on top of each injector hole, the 3 drenched with gazoline jump out but the 4th stays shut. I inspected the ground connection on ECU pins 14/55,30/55 and 48/55 I got zero ohm. I'm assuming 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 audi A3 key fob it is running fine with the G28 connected. However, the intermittent misfire problem still occurs at higher RPM. The temperature sensor for coolant (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 bar while the actual pressure is zero.
I'm not sure what to do, but i believe that i've eliminated everything else. I'm worried that i might have missed something. Please let me know if you have any ideas! TIA!
3. Fuel Pump
The fuel pump in the g28 gets 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. You can easily find the spare in a salvage shop or a parts store. It is easy to test them - simply switch your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump on the connector's edge facing up). They must be infinite Ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY) engines requires to know both the position and speed the crankshaft to determine fuel injector timing, etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you are experiencing issues with either one of these, the diagnostic scanner will show the codes that could trigger the engine shutting down.
A failing G28 sensor could cause an inaccurate speed counter for the gearbox, a gearbox that shifts faster than normal, or a misfire in the gear. If you are experiencing any of these issues it is likely that your sensor is going bad and needs replacing. The good news is they are very cheap and readily available particularly when you're looking at an Bosch unit which is what ours are. If you prefer, GM's version of this component is a good option.
5. Tachometer
A failing engine speed sensor could be the reason behind many issues with your car. It's an essential component of your audi car key cover's transmission, since it relays information to the ECU about how the audi car key case's crankshaft is turning. When this sensor fails, it can cause problems for the transmission and the rest of the car's components.
The G5 engine speed sensor is situated on the edge of the transmission above the flywheel ring gear and sends a signal directly to the ECU at pin T55/49, via a grey wire. The ECU then processes the signal to control fuel, timig and boost as well as transmitting it to the G5 tachometer inside 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 [79trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. It should show around 1000 ohms of resistance between those two pins. This is a standard component across the Audi q7 replacement key 80, 100, 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU, so the best ones might be availble in wrecking yards.