"The Ultimate Cheat Sheet On Audi G28

How to Replace an audi key shell G28 Engine Speed Sensor

Charles the Humble Technician teaches how to replace the G28 Engine Speed Sensor. The sensor is situated on the edge of the transmission just above the flywheel ring gear. It transmits a signal to the ECU through the grey wire T55/49 and then to the tachometer located on the instrument cluster.

1. Engine Speed Sensor

The grey wire is located 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 uses this information to control the flow of fuel, timig and boost. It also sends an alert to the G5 Tachometer in instrument cluster.

The sensor is used to correlate with the G40 Camshaft position Sensor. The ecu has to be aware of when the crankshaft has reached TDC and also the position of the camshaft, in order to activate the spark and injectors.

If this sensor fails the ECU will show a P00160 code which means the Crank Shaft and Intake Camshaft are not in sync and could indicate chain stretch or a jumped link on the upper timing chain. The code won't appear without the additional information provided by other sensors (G4 or G40).

Testing is a bit challenging since there are two pins for the connector and they serve different purposes but the most effective method to test it is to measure the resistance between the sensor and the ECU. It should read around 1000 ohms when the sensor is operating at its maximum. If you're having issues with this sensor, 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 significant reduction in power. It was as if the engine was running out of gas. Or, my injectors weren't firing. This morning i pull out the spark plugs, three were drenched with gazoline the fourth was dry. When i crank the engine, there are no sparks i put tissue on the top of each of the injector holes and the 3 drenched with gazoline jump out but the 4th stay closed. I tried to test the ground connections of ECU pins 14,30, and 48/55. I got 0ohm. I think the issue is elsewhere.

I also tried to reset the PID with no success. The Car Key cover audi can start when the G28 is not plugged in and is running fine when it is connected, but still has intermittent misfire issues at higher RPM. The temperature sensor for coolant (G62) shows the wrong temp value -49c even when i unplug it. Also, i noticed that the oil pressure gauge in the cockpit shows 2 bar when the actual pressure is 0.0 when I crank up the engine.

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

3. Fuel Pump

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

4. ECU

The ECU in our 20vt turbo (3B AAN ABY) engines needs to know the position and speed the crankshaft in order to make a decision about timing of the fuel injector, etc. To accomplish this, it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these go wrong, you will receive codes on the diagnostic scanner that can lead to engine shutdown.

The signs of a malfunctioning G28 sensor are an inaccurate rev counter in the gearbox and gears that shift faster than normal, and/or a misfire when you're in gear. It is probable that your sensor is failing and requires to be replaced if you notice any of these signs. The good thing is that they are very affordable and readily available particularly when you're looking at a Bosch unit which is what ours are. Alternatively, GM's version of this part would be an excellent choice.

5. Tachometer

A malfunctioning engine speed sensor could be the cause of many issues with your vehicle. It is a crucial part of the audi car key case's transmission since it relays information to the ECU about how fast or slow the vehicle's crankshaft is turning. When this sensor fails, it will affect the performance of the transmission as well as the other car's components.

The G5 engine speed sensor is located 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 a grey wire. The ECU then processes this signal to control the flow of fuel, timig and boost and then sends it on to the G5 tachometer inside the instrument cluster. You can test the sensor replacement key for audi a4 any failure by checking the continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection on pin T6a/1 (trace [79trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. You should observe approximately 1000 ohms of resistance between those two pins. This is a common part that is found across the audi key fob not working 80, 100, 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU, so the best parts could be found in wrecking yards.