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 transmission's edge over the flywheel gear. It sends a signal to the ECU via a grey wire (T55/49), then to the tachometer in the instrument cluster.

1. Engine Speed Sensor

The sensor is located at the edge of the transmission just above the flywheel ring gear G28 Engine Speed Sensor sends a signal to ECU pin T55/49 via a grey wire. The ECU then uses this information to control fuel, timig and boost. It also sends signals to the G5 tachometer inside the instrument cluster.

The sensor is used as a reference to correlate with the G40 Camshaft Position Sensor. The ecu must be aware when the crankshaft is TDC and the location of the camshaft so it can trigger spark and injectors in the right way.

If this sensor fails the ECU will show the P00160 error, which means the Crank Shaft and Intake Camshaft are not in sync and possibly indicating the chain is stretched or a jump link on the upper chain of timing. However the code will not be displayed on its own without additional information from other sensors (G4 and G40).

Testing is a bit challenging as there are two different connector pins, and they perform different functions but the most effective method to test it is by measuring resistance between the sensor and the ECU. When the sensor is fully operational, it should be reading around 1000 ohms. If you are having problems with this part, check for signs of oil or coolant in the connector bay.

2. Injectors

Yesterday accelerating full speed from highway paytoll i had a big cut in power like the engine is out of gas or injectors are not firing anymore. This morning i pull out the spark plugs, three were drenched in gazoline, the 4th one was dry. I placed a tissue over each injector hole, and when I start the engine with no sparks, the ones with gazoline jump right out. The 4th one stays closed. I checked the ground connection on ECU pins 14/55,30/55 and 48/55 I got zero ohm. I'm assuming that the issue is in another location.

I also tried to reset the PID with no success. The car will start when the G28 is disconnected, but it more info works fine when the G28 plugged in. However the intermittent misfire issue continues to occur at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature value of that is -49c even after unplugging it. I also noticed that the oil gauge in the cockpit shows 2 bar but the actual pressure is zero.

I'm not sure what to do, as i believe that i've eliminated everything else. I'm concerned that i may have missed something. Let me know If you have any suggestions! TIA!

3. Fuel Pump

The fuel pump in the g28 is activated by a signal sent by the RPM sensor. The GM-style transmitter is similar to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. It is easy to find a spare in a wrecking shop or a parts store. Testing them is easy to do - just put your DMM in resistance mode and take measurements 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

The ECU in our 20vt turbo (3B AAN ABY) audi a1 car key engines must know the speed and position of the crankshaft to determine fuel injector timing, etc. To do this, it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either audi spare keys of these go badly, you will see codes on the diagnostic scanner which can lead to engine shutdown.

A failing G28 sensor could result in an inaccurate speed counter for the gearbox or a gearbox audi advanced key that shifts more quickly than normal, or a misfire in the gear. It is possible that your sensor audi key replacement near me is failing and needs to be replaced if you notice any of these symptoms. They are cheap and easy-to-find, especially if they're an Bosch model like ours. If you prefer, GM's version of this part would be a good option.

5. Tachometer

A failing engine sensor could cause a myriad of issues within your vehicle. It's an essential component of the transmission in your Audi since it sends information to the ECU about how fast or slowly the engine is turning. This sensor could cause the transmission to malfunction and other components in the car to be affected.

The G5 engine sensor is located at the edge of the transmission, over the flywheel ring. It sends signals via an uncolored wire to the ECU pin T55/49. The ECU uses this signal to regulate the amount of fuel and boost, and also timig. It also transmits it to the G5 Tachometer located in 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 via pin T6a/1 (trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. You should detect a resistance of approximately 1000 ohms between these two points. This is a common feature across the Audi 80-100-200-RS2 model, ranging from the 1985 MC up to the 1997 UrS An and 1995 RS2 DU So, you may find some good ones in wrecking yards.