Why Nobody Cares About Audi G28

How to Replace an audi q7 key 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 edge of transmission just above the flywheel gear. It sends a signal to the ECU via a grey wire (T55/49) which is then sent to the tachometer in the instrument cluster.

1. Engine Speed Sensor

The sensor is located at the edge of the transmission above the flywheel ring gear the G28 Engine Speed Sensor sends a signal to ECU pin T55/49 through an uncolored wire. The ECU then uses this information to control the boost, fuel, and timig. It also sends signals to the G5 Tachometer located in the instrument cluster.

The sensor is used to correlate the G40 Camshaft position Sensor. The ecu must be aware when the crankshaft is TDC and where the camshaft is so it can start spark and injectors according to the situation.

If this sensor fails the ECU will show the P00160 error, which means the Crank Shaft and Intake Camshaft aren't in sync and could indicate the chain is stretched or a jump link on the upper chain of timing. The code won't appear without the additional information supplied by other sensors (G4 or G40).

It is a little tricky to test as there are various connector pins, and each has its own functions. The best method for doing this is by measuring the resistance between the ECU and the sensor. It should read about 1000 ohms when the sensor is at full operation. Examine for signs of coolant, or oil in the connector bay if you have problems with this part.

2. Injectors

Yesterday accelerating full speed from highway paytoll, i experienced an abrupt drop in power like the engine is out of gas or the injectors are not firing anymore. I pulled out the spark plugs this morning, 3 were drenched in gasoline and the fourth was unclean. When I start the engine with no sparks, I put a piece of tissue on the top of each of the injector holes and the 3 that were drenched in gazoline jump out but the 4th stays closed. I checked the ground connection of ECU pins 14,30, and 48/55. I found zero ohm. I assume that the problem is elsewhere.

I also tried to reset the PID without success. The car will start when the G28 is unplugged and is running fine when it is connected but it still is experiencing intermittent misfires at higher RPM. The coolant temperature sensor (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 bars while the actual pressure is zero.

I'm not sure what to do. I think I've ruled everything else out. However, i'm afraid that i might have missed something. Let me know if you have any ideas! TIA!

3. Fuel Pump

The fuel pump of the g28 receives signals from the RPM sensor. The GM-style transmitter is identical to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. You can easily locate the audi spare keys in a salvage shop or a parts store. Testing them is easy to do - just put your DMM in resistance mode and measure the resistance 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

Our 20vt turbo (3B AAN, audi tt key programming ABY and Audi Advanced Key ADU) engines are equipped with an ECU that needs to know the speed and position of the crankshaft in order to make decisions about timing of the fuel injector, for example. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If either of these go bad you will get codes on the diagnostic scanner which can lead to engine shutdown.

A malfunctioning G28 sensor could result in an inaccurate gearbox speed counter and a gearbox which shifts more quickly than normal, and/or an unfire when in gear. If you experience any of these issues it is likely that your sensor is deteriorating and needs replacing. The good news is they are very affordable and readily available, especially if you're looking at an Bosch sensor, which is what we have. Alternately, the GM version of this part is also a great option.

5. Tachometer

A damaged engine sensor could cause a variety of issues in your car. It's a vital component of the audi q7 key's transmission since it relays information to the ECU about how fast or slow the vehicle's crankshaft is turning. This sensor can cause the transmission to fail and other components in the car to be affected.

The G5 engine sensor is located near the edge of the transmission, just above the flywheel ring. It sends a signal via an uncolored wire to the ECU pin T55/49. The ECU then uses and processes this signal to control fuel, timig and boost and then sends it on to the G5 Tachometer located in the instrument cluster. You can check for sensor failure by examining the continuity of the sensor to the tachometer. Also, 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. You should detect an average resistance of 1000 ohms between these two points. This is a standard part that is found across the audi key replacement near me 80 100, 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU so good ones could be available in wrecking yards.