Why Nobody Cares About Audi G28

How to Replace an audi q7 key G28 Engine Speed Sensor

Charles the Humble Technician shows you how to replace the G28 Engine Speed Sensor. The sensor is situated on the edge of the transmission above the flywheel ring gear. It transmits a signal to the ECU via an uncolored wire (T55/49), then to the tachometer located in the instrument cluster.

1. Engine Speed Sensor

The sensor is located at the edge of the transmission just above the flywheel ring gear, the G28 Engine Speed Sensor sends signals 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 a signal to the G5 Tachometer located in the instrument cluster.

The sensor is used to correlate the G40 Camshaft position Sensor. The ecu must know when the crankshaft has reached TDC and also the location of the camshaft to trigger the spark and injectors.

If this sensor fails the ECU will display an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are not in sync and possibly indicating the chain stretching or a jump link on the upper timing chain. However, the code won't be displayed on its own without additional information from other sensors (G4 and G40).

It's a bit tricky to test as there are several pins on the connector and each has its own functions. The best way to do it is by measuring the resistance between the ECU and the sensor. If the sensor is operational, it should read around 1000 ohms. Check for evidence of coolant or oil in the connector bay if you have issues with this component.

2. Injectors

Yesterday accelerating full speed from highway paytoll, i experienced a big cut in power like the engine is running out of gas or injectors aren't firing any more. In the morning, i removed the spark plugs, three were drenched in gazoline, the 4th one was dry. When I crank the engine without sparks, i place a tissue on top of each injector hole, the 3 drenched with gazoline leap out, however the 4th one stays closed. I tried to test the ground connections of ECU pins 14,30, and 48/55. I got zero ohm. So i assume the problem is elsewhere.

I also tried to reset the PID without success. The car will start when the G28 is unplugged, and it works fine when the G28 connected. However, the intermittent misfire problem still occurs at higher RPM. The coolant sensor (G62) even when it is unplugged, shows a temperature of -49c. I also noticed that the gauge for oil pressure in the cockpit is showing 2 bar, whereas the actual pressure is 0.0 if 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. I'm afraid i may have missed something. Let me know should you have any suggestions! TIA!

3. Fuel Pump

The fuel pump in the g28 receives a signal from the RPM sensor. The GM-style transmitter is identical to the G4 and both are used in the 80, 100 200, UrS and RS2 cars so you can easily find one at a junkyard or in a local parts store. It is simple to test them by putting your DMM in resistance mode and measure 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 should be infinite Ohms.

4. ECU

The ECU of our 20vt turbo (3B AAN ABY ADU) engines needs to know both the position and speed the crankshaft to determine fuel injector timing, etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If you have a problem with either of these, the diagnostic scanner will show codes that could lead to an engine shutdown.

A damaged G28 sensor could result in an inaccurate gearbox speed counter or a gearbox that shifts more quickly than normal, and/or an unfire when in the gear. If you are experiencing any of these issues, it is likely your sensor is going bad and needs replacing. They're cheap and audi remote key new Key (click through the up coming article) easy to find particularly if they're a Bosch model like ours. If you prefer, GM's version of this component is a good option.

5. Tachometer

A failing engine sensor could cause a variety of issues within your vehicle. It's a vital component of your audi replacement key's transmission, as it sends information to the ECU about how fast or slow the vehicle's crankshaft is turning. This sensor can cause the transmission to malfunction and other components in the car to be affected.

The G5 engine sensor is located at the edge of the transmission, over the flywheel ring. It transmits a signal via gray wire to ECU pin T55/49. The ECU then processes this 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 any failure by checking the continuity between it and the tachometer, between ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. You should detect the resistance to be around 1000 ohms between these points. This is a standard component across the audi advance key 80 100 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU. Good parts could be found in wrecking yards.