How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician teaches you how to replace the G28 Engine Speed Sensor. This sensor is located near the edges 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 within the instrument cluster.
1. Engine Speed Sensor
The grey wire is located at the edges of the transmission, directly above the flywheel ring. This sensor sends an electrical signal through the grey wire to pin T55/49. The ECU uses this information to regulate fuel and boost. It also sends an indicator 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 the position of the camshaft, to trigger 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 alignment 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 supplied by other sensors (G4 or G40).
It's a bit tricky to test as there are several pins on the connector, and they all have 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 when the sensor is operating at its maximum. If you're experiencing issues with this component, look for evidence of coolant or oil in the connector bay.
2. Injectors
Yesterday, as i was accelerating off the highway paytoll at maximum speed, i noticed a huge drop in power. It was as if the engine was running out of gas. Or, my injectors were not firing. I pulled out the spark plugs this morning, three were soaked in gasoline, and the fourth was dry. When i crank the engine with no sparks i put tissue on top of each injector hole, the 3 drenched with gazoline leap out, however the 4th stays closed. I checked the ground connection of ECU pins 14,30, and 48/55. I found zero ohm. So i assume the problem is in another place.
I also tried to reset the PID without success. The car will start if the G28 is unplugged and is running fine when it is plugged in but it still has intermittent misfire issues at higher RPM. The coolant sensor (G62) even when unplugged, still shows an ice temperature of -49c. Also i noticed that the gauge for oil pressure in the cockpit shows 2 bar while the actual pressure is 0.0 when i rev the engine.
I'm not sure what to do. I believe that I've ruled everything else out. However, i'm afraid that I might have missed something. If anyone has any ideas please share them! TIA!
3. Fuel Pump
The fuel pump in the g28 gets a signal from the RPM sensor. The GM-style sender 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 salvage yard or in a local parts store. It is simple to test them: simply switch your DMM into resistance mode and test the distance between pins 1 and 2 (with the bump on the connector's edge facing upwards). 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 decisions about fuel injector timing etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If you are experiencing issues with either one of these, the diagnostic scanner will display codes that could lead to the engine shutting down.
Some of the symptoms of a failed G28 sensor include an inaccurate rev counter for the gearbox, gears shifting quicker than normal, and/or a misfire when in gear. If you have any of these problems, it is website most likely that your sensor is going bad and requires replacement. The good thing is that they are very cheap and easily accessible particularly if you're looking at an Bosch model, which is what ours are. You can also choose the GM version of this part is also a great option.
5. Tachometer
A damaged engine sensor could cause a myriad of issues within your vehicle. It's a crucial component of the transmission of your Audi, as it transmits information to the ECU on how fast or slowly website the car's read more engine is spinning. This sensor can cause the transmission to malfunction and other car components to be affected.
The G5 engine sensor is located at the edge of transmission, above the flywheel ring. It sends a signal via a gray wire to the ECU pin T55/49. The ECU utilizes this signal to control the amount of fuel and boost, as well as timig. It also sends it to the G5 Tachometer website in instrument cluster. You can check for sensor failure by examining the continuity from the sensor to the tachometer. Additionally, you can verify continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]) and between pin T6a/1 and pin T26a/12. You should detect the resistance to be click here around 1000 ohms between these two points. This is the same across the Audi 80-100-200-RS2 series, starting from the 1985 MC up to the 1997 UrS AN and the 1995 RS2 DU So, you may find them in wrecking yards.