How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician teaches how to replace the G28 Engine Speed Sensor. This sensor is located on the edge 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 on the instrument cluster.
1. Engine Speed Sensor
The grey wire is situated at the edges of the transmission, just above the flywheel ring. This sensor sends signals through the grey wire to pin T55/49. The ECU uses this information to regulate fuel and boost. It also sends an indication to the G5 Tachometer within the instrument cluster.
The sensor is used to correlate with the G40 Camshaft position Sensor. The ecu must know when the crankshaft has reached TDC and also the location of the camshaft so that it can 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 not in sync with the Intake Camshaft. It could also indicate a chain stretch or a jumped chain link in the upper chain. The code will not appear without the additional information supplied by other sensors (G4 or G40).
It can be a bit difficult to test since there are various connector pins, and each one has different functions. The best way to do it is to measure the resistance between the ECU and the sensor. It should read around 1000 ohms if the sensor is operating at its maximum. Examine for evidence of coolant or oil in the connector bay if there are issues with this part.
2. Injectors
Yesterday, as i was accelerating off the highway paytoll at a high speed I noticed a massive decrease in power. It was as if the engine was running out of gas. Or, my injectors weren't firing. Today, i pulled out the spark plugs. Three were soaked with gazoline and the fourth one was dry. When i crank the engine with no sparks i put tissue on top of each injector hole, the 3 drenched with gazoline jump out but the 4th stay shut. I checked the ground connection of ECU pins 14,30 and 48/55. I found 0ohm. I'm assuming the issue is elsewhere.
I also tried to reset the PID without success. The car will start when the G28 is not plugged in and it runs perfectly when it is plugged in, but still has the intermittent misfire issue at higher RPM. The coolant sensor (G62), even when unplugged, still shows an ice temperature of -49c. I also noticed that the oil pressure gauge in the cockpit shows 2 bar when the actual pressure is 0.0 when i rev the engine.
I don't know what to do. I think I've ruled everything else out. I'm afraid i may have missed something. If anyone has any suggestions, please share them! TIA!
3. Fuel Pump
The fuel pump in the g28 is activated by a signal from the RPM sensor. The GM-style transmitter functions similarly to the G4 sender and audi car keys replacement both work on the 80,100,200, UrS, and RS2 vehicles. It is easy to find a spare in a wrecking shop or parts store. It is simple to test them - simply 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
Our 20vt turbo (3B AAN, ABY, and ADU) engines are equipped with an ECU that needs to know the speed and position of the crankshaft in order to make a decision about fuel injector timing etc. To accomplish this, it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you are experiencing issues with either of these click here sensors, the diagnostic scanner will display codes that could cause the engine shutting down.
A failing G28 sensor can cause an inaccurate speed counter for your gearbox and a gearbox which shifts more quickly than normal, or an unfire when in gear. It is probable that the sensor is failing and requires to be website replaced if you encounter any of these symptoms. The good news is they are very affordable and easy to find, especially in the case of a Bosch model, which is what we have. read more Alternately, the GM version of this part is also a good option.
5. Tachometer
A faulty engine speed sensor could be the cause of many issues in your car. It's a vital component of the Audi's transmission as it sends information to the ECU about how the car's crankshaft is rotating. If this sensor fails, it could cause problems for the transmission and the rest of the car's components.
The G5 engine speed sensor is located at the outside of the transmission just above the flywheel ring gear. It sends a signal to the read more ECU at pin T55/49, via a grey wire. The ECU is then able to process this signal to control the flow of fuel, timig and boost and then sends it on to the G5 tachometer inside the instrument cluster. You can test 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 to pin T6a/1 (trace [79trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. You should observe around 1000 ohms of resistance between those points. This is a common part that is found across the Audi 80, 100 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU so good parts could be found in wrecking yards.