15 Latest Trends And Trends In Audi G28

How to Replace an audi keyless entry G28 Engine Speed Sensor

In this video, Charles the Humble Mechanic demonstrates how to replace the G28 engine speed sensor. The sensor is located near the edges of the transmission just above the flywheel ring gear. It sends a message to the ECU via a grey wire T55/49, then to the tachometer located on the instrument cluster.

1. Engine Speed Sensor

The grey wire is located on the outside of the transmission, above the flywheel ring. The sensor sends signals through the grey wire to pin T55/49. The ECU utilizes this information to regulate fuel and boost. It also sends an indication 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 of when the crankshaft has reached TDC, and the position of the camshaft, in order to activate the spark and injectors.

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

Testing is a bit challenging since there are two connector pins, and they serve different purposes but the best way to test it is to measure the resistance between the sensor and the ECU. It should read approximately 1000 ohms if the sensor is operating at its maximum. Examine for signs of coolant or oil in the connector bay if you are experiencing issues with this component.

2. Injectors

Yesterday, when accelerating from highway paytoll at full speed, i noticed a huge decrease in power. It was as if the engine had run out of gas. Or, my injectors weren't firing. In the morning, i removed the spark plugs, three were drenched in gazoline, the fourth one was dry. I put a piece of tissue over each injector hole, and when I turn the engine on without sparks, the 3 that have gazoline pop right out. The fourth one remains closed. I checked the ground connection on ECU pins 14/55,30/55 and 48/55 I got zero Ohm. So i assume the problem is somewhere else.

I also tried to reset 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 sensor (G62) even when it is unplugged, shows temperatures of -49c. I also noticed that the oil gauge in the cockpit shows 2 bar but the actual pressure is zero.

I'm not certain what to do, but i believe that i've eliminated everything else. I'm concerned that i may have missed something. Let me know if you have any ideas! TIA!

3. Fuel Pump

The fuel pump in the g28 is activated by a signal from the RPM sensor. The GM-style transmitter is similar to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. It is easy to find a spare in a wrecking shop or a parts store. It is simple to test them - put your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector's end 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 have an ECU that needs to be aware of the speed and position of the crankshaft to make decisions regarding timing of the fuel injector, for example. In order to do this it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these sensors go wrong, you will receive codes on the diagnostic scanner which could cause engine shut down.

A failing G28 sensor could result in an inaccurate speed counter for the gearbox, a gearbox that shifts more quickly than normal, and/or a misfire while in the gear. If you are experiencing any of these issues it is likely that your sensor is deteriorating and should be replaced. The good thing is that they are very cheap and easily accessible, especially when you're looking at the Bosch sensor, which is what ours are. Alternatively, GM's version of this part is an option.

5. Tachometer

A damaged engine sensor could cause a variety of issues within your vehicle. It's an essential component of the transmission in your audi connect key because it relays information to the ECU on how fast or slowly the engine is spinning. If this sensor fails, it could affect the performance of the transmission and the other car's components.

The G5 engine sensor is located near the edge of the transmission, just above the flywheel ring. It transmits an electrical signal through a gray wire to the ECU pin T55/49. The ECU utilizes this signal to regulate the amount of fuel and boost, and also timig. It also relays it to the G5 Tachometer in instrument cluster. You can check the sensor for any failure by checking the continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. There should be an average resistance of 1000 ohms in these areas. This is a common feature across the audi q7 replacement key 80-100-200-RS2 range, from the 1985 MC up to the 1997 UrS AN and the 1995 RS2 DU, so you might find good ones in wrecking yards.