The Most Innovative Things That Are Happening With Audi G28

How to Replace an audi a3 keys G28 Engine Speed Sensor

In this video, Charles the humble mechanic demonstrates how to replace the G28 engine speed sensor. This sensor is located at the edge of transmission over the flywheel gear. It transmits a signal to the ECU via the grey wire (T55/49) which is then sent to the tachometer within the instrument cluster.

1. Engine Speed Sensor

The grey wire is situated at the edges of the transmission, just above the flywheel ring. The sensor transmits a signal via the grey wire to pin T55/49. The ECU uses this information to regulate fuel and boost. It also sends a signal to the G5 Tachometer located in the instrument cluster.

The sensor serves as a reference to correlate with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft has reached TDC and also the position of the camshaft, so that it can activate the spark and injectors.

If this sensor fails, the ECU will display a P00160 error message. This indicates that the Crank Shaft is out of line with the Intake Camshaft. It could also indicate an issue with the chain or a jumpy chain link in the upper chain of timing. However, the error code won't be displayed on its own without additional information from other sensors (G4 and G40).

It's a bit tricky to test since there are several pins on the connector and each one has different functions. The best way to do it is by measuring the resistance between the ECU and the sensor. 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 there are issues with this part.

2. Injectors

Yesterday, while accelerating from the highway paytoll at a high speed I noticed a massive reduction in power. It was like the engine had run out of gas. Or, my injectors were not firing. I took out the spark plugs this morning and found that 3 were drenched in gasoline and the fourth was unclean. When I start the engine without sparks i put tissue on the top of each hole in the injector, the 3 drenched with gazoline leap out, however the 4th one stays shut. I checked the ground connection of ECU pins 14,30 and 48/55. I found 0ohm. I assume that the problem is somewhere else.

I also tried to reset the PID but with no luck. The car will start when the G28 is unplugged, and it is running fine with the G28 connected. However, the intermittent misfire problem still occurs at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature value of -49c, even if I unplug it. Also i noticed that the gauge for oil pressure in the cockpit shows 2 bar, whereas the actual pressure is 0.0 if i crank up the engine.

I'm not certain what to do, as i believe that i've completely ruled out all other possibilities. I'm concerned that i may have missed something. If anyone has any ideas please share them! TIA!

3. Fuel Pump

The fuel pump of the g28 gets a signal from the RPM sensor. The GM-style sender is the same as the G4 and both function in the 80, 100 200, UrS and RS2 cars so you can easily find one at a junkyard or from a parts store. Testing them is easy to do - just put 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 end). They should be infinite Ohms.

4. ECU

Our 20vt turbo (3B, AAN, ABY and ADU) engines are equipped with an ECU that must know the position and speed of the crankshaft to make a decision about timing of the fuel injector, for example. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you have a problem with either of these, the diagnostic scanner will display codes that could lead to the engine shutting down.

A damaged G28 sensor could cause an inaccurate speed counter for your gearbox and a gearbox which shifts faster than normal, and/or a misfire while in the gear. It is probable that the sensor is failing and requires to be replaced if you notice any of these signs. They are cheap and easy-to-find particularly in the case of a Bosch unit like ours. If you prefer, GM's version of this part would be a good option.

5. Tachometer

A failing engine speed sensor could be a cause for numerous problems in your vehicle. It's an essential component of the transmission in your Audi A1 keys tt audi a5 key fob fob (click the next document) because it relays information to the ECU about how fast or slow the engine is spinning. This sensor can cause the transmission to malfunction and other components in the car to be affected.

The G5 engine speed sensor is situated on the edge of the transmission, above the flywheel ring gear. It transmits a signal to the ECU at pin T55/49 via an uncolored wire. The ECU is then able to process the signal to control fuel, timig and boost as well as sends it on to the G5 Tachometer located in the instrument cluster. You can test the sensor for failure by checking continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. You should see approximately 1000 ohms of resistance between these two points. This is a standard part that is found across the audi keyfob 80, 100, 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and audi a3 key fob Replacement 1995 RS2 ADU so good ones could be available in wrecking yards.