What Is Audi G28? History Of Audi G28

How to Replace an Audi G28 Engine Speed Sensor

In this video Charles the humble mechanic demonstrates how to replace the G28 engine speed sensor. This sensor is located near the transmission's edge just above the flywheel gear. It sends a message to the ECU through the grey wire T55/49 and then to the tachometer in the instrument cluster.

1. Engine Speed Sensor

It is located on the outside of the transmission above the flywheel ring gear the G28 Engine Speed Sensor sends a signal to ECU pin T55/49 using the grey wire. The ECU then uses this information to control the flow of fuel, timig 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 needs 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 an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are out of sync and possibly indicating chain stretch or a jumped link on the upper chain of timing. The code won't appear without the additional information supplied by other sensors (G4 or G40).

Testing is a bit challenging as there are two different connector pins, and they perform different functions but the best method to test it is by measuring resistance between the sensor and the ECU. When the sensor is fully operational, it should read about 1000 ohms. Look for signs of coolant, or oil in the connector bay if there are issues with this part.

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 running out of gas or injectors are not firing any more. Today, i pulled out the spark plugs, three were drenched in gazoline, the fourth was dry. When I start 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 got zero ohm. Therefore, i think the issue is in another place.

I also tried to reset the PID without success. The car is able to start when the G28 is disconnected and runs fine when it is connected, but still is experiencing intermittent misfires at higher RPM. The coolant sensor (G62), even when it is unplugged, shows temperatures of -49c. Also i noticed that the gauge for oil pressure in the cockpit is showing 2 bar while the actual pressure is 0.0 when i rev the engine.

I'm not certain what to do, but i feel i have pretty much completely ruled out all other possibilities. I'm worried that i might have missed something. If anyone has any ideas please share them! TIA!

3. Fuel Pump

The fuel pump on the g28 is activated by a signal from the RPM sensor. The GM-style transmitter is similar to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. You can easily find the spare in a salvage shop or parts store. It is simple to test them - put your DMM in resistance mode and measure the resistance 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 must 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 to make decisions regarding timing of the fuel injector, for example. To accomplish this, it check here utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you encounter a problem with either one of these, the diagnostic scanner will display codes that could cause an engine shut down.

A damaged G28 sensor could result in an inaccurate speed counter for the gearbox and a gearbox which shifts more quickly than normal, or an unfire when in the gear. If you experience any of these here problems, it is likely that your sensor is failing and needs replacing. The good thing is that they are very affordable and readily available particularly in the case of a Bosch unit which is what ours are. Alternately, the GM version of this part is also a good choice.

5. Tachometer

A failing engine speed sensor could be a cause for numerous issues in your car. It is a crucial part get more info of the audi a4 spare key Audi's transmission because it communicates to the ECU about how fast or slow the car's crankshaft is rotating. When this sensor fails, it will affect the performance of the transmission, as well as the other car's components.

The G5 engine speed sensor is located on the outside of the transmission above the flywheel ring gear. It transmits a signal to the ECU at pin T55/49, via a grey wire. The ECU then processes this signal to control fuel, timig, and boost as well as transmitting it to the G5 tachometer get more info in the instrument cluster. You can check for sensor failure by examining the continuity of the sensor to the tachometer. Additionally, you can check continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]) and between pin T6a/1 and pin T26a/12. You should observe approximately 1000 ohms resistance between these two points. This is a standard component across the Audi 80 100, 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU. Good ones could be available in wrecking yards.