How to Replace an Audi Replacement Key Fob G28 Engine Speed Sensor

Charles the Humble Technician teaches how to replace the G28 Engine Speed Sensor. The sensor is located on the edge of the transmission just above the flywheel ring gear. It transmits 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 located at the edges of the transmission, above the flywheel ring. This 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 an alert to the G5 Tachometer in instrument cluster.

The sensor serves as a reference for comparing with the G40 Camshaft Position Sensor. The ecu needs to know when the crankshaft has reached TDC and also the location of the camshaft to trigger the spark and injectors.

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

Testing is a bit tricky as there are two different pins for the connector and they perform different functions but the most effective method to test it is by measuring resistance between the sensor and the ECU. It should read approximately 1000 ohms if the sensor is operating at its maximum. Look for signs of coolant or oil in the connector bay if you are experiencing issues with this part.

2. Injectors

Yesterday, while accelerating from the highway paytoll at a high speed, i noticed a huge drop in power. It was like the engine had run out of gas. Or, my injectors weren't firing. This morning i pull out the spark plugs, 3 were drenched in gazoline, the 4th one was dry. I put tissue over each injector hole, and when i start the engine without sparks, the three that have gazoline pop right out. The 4th one remains closed. I checked the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I get zero ohm. I'm assuming the issue is elsewhere.

I also tried to reset the PID without success. The car is able to start when the G28 is disconnected and runs fine when it is plugged in but it still has intermittent misfire issues at higher RPM. The coolant temperature sensor (G62) shows the wrong temp value -49c even when i unplug it. I also noticed that the gauge for oil pressure in the cockpit is showing 2 bar while the actual pressure is 0.0 when I crank up the engine.

I'm not sure what to do. I think I've all other possibilities out. But i'm worried that I might have missed something. If anyone has any ideas please share them! TIA!

3. Fuel Pump

The fuel pump of the g28 receives signals from the RPM sensor. The GM-style transmitter functions similarly to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. You can easily locate an extra in a wrecking shop or a parts store. It is simple to test them - just 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 should be infinite Ohms.

4. ECU

The ECU in our 20vt turbo (3B AAN ABY) engines needs to be aware of the speed and position of the crankshaft in order to make a decision about timing of fuel injectors, etc. In order to do this it uses a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you encounter a problem with either of these sensors, the diagnostic scanner will show the codes that could trigger an engine shutdown.

A failing G28 sensor could result in an inaccurate speed counter for your gearbox and a gearbox which shifts faster than normal, and/or a misfire in the gear. If you experience any of these issues, it is likely your sensor is deteriorating and requires replacement key for audi a3. They are cheap and easy-to-find particularly if they're a Bosch sensor like ours. You can also choose the GM version of this part is also a good choice.

5. Tachometer

A malfunctioning engine speed sensor could be the cause of many issues with your audi car key cover. It's a crucial component of the transmission of your audi key copy, as it transmits information to the ECU on how fast or slowly the engine is turning. This sensor could cause the transmission to malfunction and other components in the car to be affected.

The G5 engine sensor is located at the edge of transmission, above the flywheel ring. It transmits an electrical signal through an uncolored wire to the ECU pin T55/49. The ECU is then able to process the signal to control fuel, timig and boost, and also sends it on to the G5 tachometer inside the instrument cluster. You can check the sensor for failure by examining the continuity between it and the tachometer, between the ECU pin T55/49 and Replace Audi key the instrument cluster connection via pin T6a/1 (trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. There should be a resistance of approximately 1000 ohms between these points. This is a common feature across the audi q3 key 80-100-200-RS2 model, ranging from the 1985 MC all the way up to the 1997 UrS AN and the 1995 RS2 Du So, you may find good ones in wrecking yards.