About Ralston Suarez

Description

10 Things You Learned In Preschool That'll Help You Understand Audi G28
How to Replace an Audi G28 Engine Speed Sensor

In this video Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. The sensor is located at the top of the transmission, above the flywheel ring gear. It transmits a signal 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 located on the outside of the transmission, just above the flywheel ring. The sensor sends a signal via the grey wire to pin T55/49. The ECU utilizes this information to regulate the amount of fuel and boost. It also sends an indication to the G5 Tachometer located in the instrument cluster.

The sensor is used to correlate with the G40 Camshaft position Sensor. The ecu must know when the crankshaft is TDC and where the camshaft is located so that it can trigger spark and injectors in the right way.

If this sensor fails the ECU will show a P00160 code which means the Crank Shaft and Intake Camshaft are out of sync, possibly indicating chain stretch or a jumped link on the upper chain of timing. However, the code won't appear on its own without additional information from other sensors (G4 and G40).

It's a bit tricky to test as there are different pins on the connector, and each has its own functions. The most effective method to test it is to measure the resistance between the ECU and the sensor. When the sensor is operational, it should be reading about 1000 ohms. If you're having issues with this part, check for signs of coolant or oil in the connector bay.

2. Injectors

Yesterday, when i was accelerating to the fullest speed from highway paytoll, i experienced an abrupt drop in power like the engine is out of gas or injectors aren't firing anymore. audi a4 key replacement The Key Lab took out the spark plugs this morning, 3 were soaked with gasoline and the fourth was dry. When I start the engine with no sparks, I put a piece of tissue on the top of each hole in the injector and the 3 that were drenched in gazoline jump out but the 4th one stays shut. I checked the ground connection of ECU pins 14,30 and 48/55. I found zero ohm. I assume that the problem is in another location.


I also tried to reset the PID without success. The car will start when the G28 is unplugged, and it runs fine with the G28 plugged in. However the intermittent misfire issue persists at higher RPM. The coolant sensor (G62), even when unplugged, still shows temperatures of -49c. I also noticed that the gauge for oil pressure in the cockpit is showing 2 bar when the actual pressure is 0.0 if i crank up the engine.

I don't know what to do. I think I've all other possibilities out. However, i'm afraid that I may have missed something. Let me know if you have any ideas! TIA!

3. Fuel Pump

The fuel pump in the g28 gets a signal from the RPM sensor. The GM-style transmitter is identical to the G4 and both function in the 80 100, 200, UrS and RS2 cars which is why you can easily locate one at a salvage yard or in a local parts store. It is simple to test them - just put your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump at the connector's end 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 decisions regarding timing of the fuel injectors, etc. To do this, it uses a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you are experiencing issues with either of these sensors, the diagnostic scanner will show codes that could cause an engine shut down.

A damaged G28 sensor could result in an inaccurate speed counter for the gearbox or a gearbox that shifts faster than normal, and/or an unfire when in the gear. If you are experiencing any of these issues, it is likely your sensor is deteriorating and should be replaced. The good news is that they are very cheap and easily accessible, especially if you're looking at a Bosch sensor, which is what ours are. If you prefer, GM's version of this component is a good option.

5. Tachometer

A failing engine speed sensor could be the cause of numerous issues in your vehicle. It is an important part of the transmission of your Audi since it sends information to the ECU about how fast or slow the engine of the car is turning. This sensor could cause the transmission to fail and other components of the car to be affected.

The G5 engine sensor is located at the edge of the transmission, just above the flywheel ring. It transmits signals via a gray wire to the ECU pin T55/49. The ECU utilizes this signal to regulate the flow of fuel and boost and also to timigrate. It also transmits it to the G5 Tachometer in instrument cluster. You can check the sensor for failure by checking continuity between it and the tachometer. You can also check continuity between 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. There should be the resistance to be around 1000 ohms between these two points. This part is common across the Audi 80-100-200-RS2 series, starting beginning with the 1985 MC and up to the 1997 UrS AN and 1995 RS2 Du So, you may find good ones in wrecking yards.