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. The sensor is located near the edges of the transmission just above the flywheel ring gear. It transmits a signal to the ECU through an uncolored wire T55/49, then to the tachometer located on the instrument cluster.

1. Engine Speed Sensor

The grey wire is situated on the outside of the transmission, directly above the flywheel ring. The sensor sends signals through 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 as a reference to correlate with the G40 Camshaft Position Sensor. The ecu has to know when the crankshaft reached TDC and also where the camshaft lies to trigger the spark and injectors.

If this sensor fails the ECU will display a P00160 code which means the Crank Shaft and Intake Camshaft aren't in sync and possibly indicating the chain stretching or a jump link on the upper chain of timing. However the code will not appear on its own, without additional information from other sensors (G4 and G40).

Testing is a bit challenging as there are two different pins for the connector and they serve different purposes but the best method to test it is to measure the resistance between the sensor and the ECU. When the sensor is fully operational, it should read around 1000 ohms. Examine for signs of coolant, or oil in the connector bay if you are experiencing problems with this part.

2. Injectors

Yesterday, while accelerating at full speed from the highway paytoll, i experienced a big cut in power like the engine is running out of gas or the injectors aren't firing anymore. I pulled out the spark plugs this morning, three were soaked with gasoline and the fourth was unclean. When i crank the engine with no sparks, i place a tissue on the top of each of the injector holes and the 3 drenched with gazoline leap out, however the 4th stays closed. I tried to test the ground connections of ECU pins 14,30 and 48/55. I got 0ohm. I'm assuming that the issue is in another location.

I also tried to reset the PID without success. The car will start when the G28 is disconnected, but it works fine when the G28 plugged in. However, the intermittent misfire problem still occurs at higher RPM. The coolant sensor spare audi key cost (G62) even when it is unplugged, shows an ice temperature of -49c. I also noticed that the oil pressure gauge in the cockpit is showing 2 bar when the actual pressure is 0.0 when i rev the engine.

I'm not sure what to do. I feel like i've pretty much ruled everything else out. I'm afraid i may have missed something. Let me know If you have any suggestions! TIA!

3. Fuel Pump

The fuel pump in the g28 receives a signal from the RPM sensor. The GM-style transmitter is identical to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. You can easily locate an extra in a wrecking shop or parts store. Test them out to do - just put your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector end up) and 2 (2nd from left on the black connector's side). They should be infinite ohms.

4. ECU

Our 20vt turbo (3B, AAN, ABY and ADU) engines are equipped with an ECU that needs to be aware of the speed and position of the crankshaft to make a decision about timing of the fuel injectors, etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If audi a3 replacement key either of these go badly, you will see codes on the diagnostic scanner which can lead to engine shutdown.

The signs of a failed G28 sensor include an inaccurate rev counter in the gearbox, gears shifting quicker audi a4 key replacement than normal and/or a misfire when you are in gear. It is probable that the sensor is failing and requires to be replaced if you encounter any of these signs. The good thing is that they are very affordable and readily available particularly in the case of the Bosch model, like ours. If you prefer, GM's version of this component is a good option.

5. Tachometer

A faulty engine speed sensor could be website the reason behind a slew of issues with your vehicle. It's an essential component of the transmission in your Audi, as it transmits information to the ECU about how fast or slowly the car's engine is turning. If this sensor fails, it can disrupt the performance of the transmission, as well as the get more info rest of the car's components.

The G5 engine sensor is located at the outskirts of transmission, above the flywheel ring. It sends a signal via a gray wire to the ECU pin T55/49. The ECU uses this signal to regulate fuel and boost, and also timig. It also sends it to the G5 Tachometer in instrument cluster. You can test for sensor failure by checking continuity from the sensor to the tachometer. Also, you can verify 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 see a resistance of approximately 1000 ohms between these points. This is a common part across the Audi 80, 100 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU, so the best parts could be found in wrecking yards.