How to Replace an audi key programming G28 Engine Speed Sensor

Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. This sensor is situated near the transmission's edge, above the flywheel gear. It sends a signal to the ECU via the grey wire (T55/49), then to the tachometer located in the instrument cluster.

1. Engine Speed Sensor

The grey wire is situated on the outside of the transmission, just above the flywheel ring. The sensor transmits a signal via the grey wire to pin T55/49. The ECU then uses this information to control fuel, timig and boost. It also sends a signal to the G5 tachometer in the instrument cluster.

The sensor is used as a reference for comparing with the G40 Camshaft Position Sensor. The ecu needs to know when the crankshaft is TDC and where the camshaft is located so that it can start spark and injectors in the right way.

If this sensor fails when it fails, the ECU will display a P00160 error message. This indicates that the Crank Shaft is out of alignment with the Intake Camshaft. It could also indicate an issue with the chain or a jumpy chain link in the upper chain of timing. The code won't show without the additional information provided by other sensors (G4 or G40).

Testing can be a bit difficult since there are two pins for the connector and they perform different functions however the best method to test it is to measure resistance between the sensor and the ECU. It should read about 1000 ohms if the sensor is at full operation. Look for signs of coolant or oil in the connector bay if there are issues with this component.

2. Injectors

Yesterday, when accelerating from highway paytoll at maximum speed, i noticed a huge reduction in power. It was like the engine was running out of gas. Or, my injectors weren't firing. I pulled out the spark plugs this morning, 3 were soaked in gasoline, and the fourth was unclean. I placed a tissue over each hole in the injector and when i start the engine without sparks, the ones with gazoline jump right out. The fourth one remains closed. I tested the ground connection 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 but with no luck. The car will start when the G28 is disconnected, but it is running fine with the G28 connected. However the intermittent misfire issue still occurs at higher RPM. The temperature sensor for coolant (G62) shows the wrong temp value -49c even when i unplug it. I also noticed that the oil gauge in the cockpit shows 2 bar while the actual pressure is 0.

I'm not sure what to do, but i believe that i've eliminated everything else. However, i'm afraid that I might have missed something. If anyone has any ideas please chime in! TIA!

3. Fuel Pump

The fuel pump of the g28 receives signals from the RPM sensor. The GM-style sensor 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 junkyard or from a parts store. It is simple to test them - simply put your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump at the connector end facing up). They should be infinite ohms.

4. ECU

The ECU in our 20vt turbo (3B AAN ABY) engines requires to be aware of the position and speed 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 accomplish this. If you encounter a problem with either one of these, the diagnostic scanner will show codes that could lead to an engine shut down.

A failing G28 sensor can cause an inaccurate speed counter for the gearbox, a gearbox that shifts faster than normal, or a misfire in gear. It is possible that your sensor is failing and needs to be replaced if you encounter any of these signs. The good thing is that they are very cheap and readily available, especially if you're looking at a Bosch model, which is what ours are. If you prefer, GM's version of this part is an option.

5. Tachometer

A malfunctioning engine speed sensor Replacement Key audi could be the reason behind many issues with your vehicle. It's a vital component of the audi key fob replacement's transmission since it relays information to the ECU about how fast or slow the vehicle's crankshaft is rotating. This sensor could cause the transmission to malfunction and other components in the car to be affected.

The G5 engine speed sensor is located on the edge of the transmission just above the flywheel ring gear and transmits a signal to the ECU at pin T55/49 through a grey wire. The ECU uses this signal to regulate the amount of fuel and boost, as well as timig. It also transmits it to the G5 Tachometer inside the instrument cluster. You can check the sensor for failure by checking continuity between it and the tachometer, between ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. You should see the resistance to be around 1000 ohms in these areas. This is a common feature across the Audi Tt Key Programming 80-100-200-RS2 series, starting beginning with the 1985 MC and up to the 1997 UrS An and 1995 RS2 DU You may also find some good ones in wrecking yards.