The History Of Audi G28
The History Of Audi G28
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How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician shows you how to replace the G28 Engine Speed Sensor. This sensor is situated on the outside of the transmission, above the flywheel gear. It transmits a signal to the ECU via the grey wire T55/49 and then to the tachometer in the instrument cluster.
1. Engine Speed Sensor
Located on the edge of the transmission above the flywheel ring gear the G28 Engine Speed Sensor sends an electrical signal to ECU pin T55/49 through an uncolored wire. The ECU utilizes this information to regulate fuel and boost. It also sends an indication to the G5 Tachometer within the instrument cluster.
The sensor is used as a reference to correlate with the G40 Camshaft Position Sensor. The ecu has to be aware of when the crankshaft has reached TDC, and the position of the camshaft, to trigger the spark and injectors.
If this sensor fails, the ECU will display a P00160 error message. This means that the Crank Shaft is not in sync with the Intake Camshaft. It could also be a sign of the possibility of a chain stretch or jumped chain link in the upper timing chain. The code won't show without the additional information provided by other sensors (G4 or G40).
It is a little tricky to test because there are several pins on the connector, and they all have different functions. The most effective method to test it is by measuring the resistance between the ECU and the sensor. It should read around 1000 ohms when it is operating at its maximum. Examine for signs of coolant or oil in the connector bay if you have problems with this part.
2. Injectors
Yesterday, as i was accelerating off the highway paytoll at maximum speed I noticed a massive decrease in power. It was like the engine had run out of gas. Or my injectors were not firing. This morning i pull out the spark plugs, 3 were drenched in gazoline, the fourth was dry. I placed a tissue over each injector hole, and when I turn the engine on without sparks, the ones with gazoline jump out. The fourth one remains closed. I checked the ground connection on ECU pins 14/55,30/55 and 48/55 I get zero ohm. I'm assuming the issue is in another place.
I also tried to reset the PID but without success. The car click here will start when the G28 is disconnected and it runs perfectly when it is plugged in but it still has the intermittent misfire issue at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature of -49c even when i unplug it. Also, i noticed that the gauge for oil pressure more info in the cockpit is showing 2 bar, whereas the actual pressure is 0.0 when I crank up the engine.
I'm not sure what to do. I think I've eliminated everything else. However, i'm afraid that I may have missed something. If anyone has suggestions, please let me know! TIA!
3. Fuel Pump
The fuel pump in the g28 is activated by a signal by the RPM sensor. The GM-style transmitter is identical to the G4 and they both work 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 by putting your DMM in resistance mode and measure between pins 1 (with the bump on the connector end up) and 2 (2nd from left on the black connector's side). They must be infinite ohms.
4. ECU
Our 20vt turbo (3B AAN, ABY and ADU) engines have an ECU that has to know the speed and position of the crankshaft in order to make decisions regarding timing of the fuel injector, for example. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to audi convenience key accomplish this. If you are experiencing issues with either of these sensors, the diagnostic scanner will show the codes that click here could trigger an engine shutdown.
A malfunctioning G28 sensor could cause an inaccurate gearbox speed counter or a gearbox that shifts faster than normal, and/or a misfire in gear. If you have any of these issues it is likely that your sensor is deteriorating and should be replaced. They are cheap and easy-to-find especially when they're an Bosch unit like ours. If you prefer, GM's version of this component is a good option.
5. Tachometer
A malfunctioning engine speed sensor could be a cause for numerous issues in your vehicle. It's an essential component of the transmission of your Audi, as it transmits information to the ECU about how fast or slowly the engine is spinning. This sensor could cause the transmission to malfunction and other car components to be affected.
The G5 engine speed sensor is located on the edge of the transmission above the flywheel ring gear and sends a signal to the ECU at pin T55/49, via a grey wire. The ECU uses this signal to regulate the amount of fuel and boost, and also timig. It also transmits it to the G5 Tachometer inside the instrument cluster. You can test the sensor for failure get more info by examining the continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. You should observe approximately 1000 ohms resistance between these two points. This is a common part that is found across the Audi 80, 100, 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU so good ones could be available in wrecking yards.