How to Replace an Audi Q7 Key G28 Engine Speed Sensor

In this video, Charles the Humble Mechanic demonstrates how to replace the G28 engine speed sensor. This sensor is situated audi key replacement near me the transmission's edge just above the flywheel gear. It transmits a signal to the ECU via an uncolored wire T55/49, then to the tachometer in the instrument cluster.

1. Engine Speed Sensor

The grey wire is located at the edges of the transmission, above the flywheel ring. The sensor sends an electrical signal through the grey wire to pin T55/49. The ECU utilizes this information to regulate the amount of fuel and boost. It also sends an indicator to the G5 Tachometer located in the instrument cluster.

The sensor is used to correlate with the G40 Camshaft position Sensor. The ecu must know when the crankshaft is TDC and the location of the camshaft so it can activate spark and injectors according to the situation.

If this sensor fails to function, the ECU will display a P00160 error message. This indicates that the Crank Shaft is not in alignment with the Intake Camshaft. It could also indicate the possibility of a chain stretch or jump in the chain link of the upper chain. The code won't appear without the additional information provided by other sensors (G4 or G40).

It's a bit tricky to test because there are several 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 operational, it should be reading around 1000 ohms. If you're experiencing issues with this component, look for evidence of coolant or oil in the connector bay.

2. Injectors

Yesterday, while accelerating from the highway paytoll at full speed I noticed a massive drop in power. It was like the engine had run out of gas. Or, my injectors weren't firing. In the morning, i removed the spark plugs, three were soaked with gazoline and the fourth was dry. When i crank the engine, there are no sparks, i place a tissue on top of each injector hole and the 3 that were drenched in gazoline pop out, but the 4th stays shut. I tested the ground connection of ECU pins 14,30 and 48/55. I found 0ohm. I'm assuming the issue is elsewhere.

I also tried to reset the PID but with no luck. The car will start when the G28 is unplugged, and it is running fine with the G28 plugged in. However, the intermittent misfire problem still occurs at higher RPM. The coolant sensor (G62) even when it is unplugged, shows a temperature of -49c. Also, i noticed that the gauge for oil pressure in the cockpit shows 2 bar while the actual pressure is 0.0 if i crank up the engine.

I'm not sure what to do, as i feel i have pretty much completely ruled out all other possibilities. I'm worried that i might have missed something. Please let me know If you have any suggestions! TIA!

3. Fuel Pump

The fuel pump on the g28 is activated by a signal by the RPM sensor. The GM-style transmitter is the same as the G4 and both function in the 80, 100 200, UrS and RS2 cars which is why you can easily locate one at a salvage yard or at a parts store. Test them out - put your DMM in resistance mode and take measurements between pins 1 (with the bump on the connector's side up) and 2 (2nd from left on the black connector's end). They must be infinite Ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY and ADU) engines are equipped with an ECU that has to be aware of the speed and audi q7 Replacement key position of the crankshaft in order to make decisions regarding fuel injector timing etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If you are experiencing issues with either of these sensors, the diagnostic scanner will display codes that could lead to the engine shutting down.

A damaged G28 sensor could result in an inaccurate speed counter for the gearbox and a gearbox which shifts faster than normal, or a misfire while in the gear. It is likely that your sensor is failing and requires to be replaced if you notice any of these signs. They are cheap and easy-to-find particularly when they're a Bosch model like ours. Alternatively, the GM version of this part is also a great option.

5. Tachometer

A failing engine sensor could cause a myriad of issues within your vehicle. It's a vital component of your audi remote key's transmission, because it communicates to the ECU about how the audi car key's crankshaft is turning. If the sensor fails, it could cause problems for the transmission, as well as the rest of the car's components.

The G5 engine speed sensor is situated on the edge of the transmission just above the flywheel ring gear. It sends a signal directly to the ECU at pin T55/49 through an uncolored wire. The ECU then uses and processes this signal to control fuel, timig and boost and then transmitting it to the G5 tachometer inside the instrument cluster. You can test for sensor failure by examining the continuity of 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. It should show approximately 1000 ohms of resistance between those two pins. This part is common across the audi key fob 80-100-200-RS2 model, ranging from the 1985 MC up to the 1997 UrS AN and the 1995 RS2 DU You may also find good ones in wrecking yards.