How to Replace an audi replacement Car keys G28 Engine Speed Sensor

Charles the Humble Technician teaches how to replace the G28 Engine Speed Sensor. This sensor is located on the outside of the transmission over the flywheel gear. It sends a signal to the ECU via the grey wire (T55/49) which is then sent to the tachometer in the instrument cluster.

1. Engine Speed Sensor

The grey wire is situated on the edge of transmission, just above the flywheel ring. The sensor sends signals through the grey wire to pin T55/49. The ECU then uses this information to control the boost, Audi Replacement Car Keys fuel, and timig. It also sends signals to the G5 Tachometer located in the instrument cluster.

The sensor serves as a reference to correlate with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft has reached TDC and also the location of the camshaft so that it can activate the spark and injectors.

If this sensor fails the ECU will display the P00160 error, which means the Crank Shaft and Intake Camshaft are out of sync and could indicate 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 because there are two connector pins, and they serve different purposes but the best way to test it is to measure the resistance between the sensor and the ECU. It should read about 1000 ohms if the sensor is in full operation. If you're experiencing issues with this component, look for signs of coolant or oil in the connector bay.

2. Injectors

Yesterday, while accelerating at full speed from the highway paytoll, i experienced massive power loss like the engine is out of gas or injectors aren't firing any more. This morning i pull out the spark plugs, three were soaked with gazoline and the fourth was dry. I put a piece of tissue over each injector hole, and when i turn the engine on without sparks, the ones with gazoline jump right out. The 4th one stays shut. I tested the ground connection on ECU pins 14/55,30/55 and 48/55 I get zero ohm. I assume that the problem is in another location.

I also tried to reset the PID but with no luck. The car can start if the G28 is unplugged and is running fine when it is connected however it has the intermittent misfire issue at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature value of -49c, even if I unplug it. Also i noticed that the gauge for oil pressure in the cockpit shows 2 bar when the actual pressure is 0.0 when i rev the engine.

I don't know what to do. I think I've eliminated everything else. But i am afraid i might have missed something. If anyone has any ideas please chime in! TIA!

3. Fuel Pump

The fuel pump in the g28 can be activated by a signal by the RPM sensor. The GM-style transmitter functions similarly to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. You can easily find a spare in a wrecking shop or parts store. It is simple to test them by putting your DMM in resistance mode and take measurements between pins 1 (with the bump on the connector's end up) and 2 (2nd from left on the black end of the connector). They should be infinite Ohms.

4. ECU

The ECU in our 20vt turbo (3B AAN ABY) engines needs to know the speed and position of the crankshaft to make decisions regarding fuel injector timing, etc. In order to do this it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these sensors go badly, you will see codes on the diagnostic scanner which could cause engine shut down.

A failing G28 sensor can cause an inaccurate speed counter for your gearbox and a gearbox which shifts more quickly than normal, and/or an unfire when in gear. It is likely that your sensor is failing and needs to be replaced if you notice any of these signs. The good news is that they are quite affordable and easy to find, especially if you're looking at an Bosch model, which is what ours are. Alternatively, GM's version of this component is an excellent choice.

5. Tachometer

A faulty engine speed sensor could be the cause of numerous problems in your car. It's a vital component of your audi remote key's transmission, because it communicates to the ECU about how the car's crankshaft is rotating. This sensor can cause the transmission to fail and Audi Replacement Car Keys other components in the car to be affected.

The G5 engine sensor is located near the edge of the transmission, just above the flywheel ring. It transmits an electrical signal through a gray wire to the ECU pin T55/49. The ECU then processes this signal to control fuel, timig and boost as well as sends it on to the G5 Tachometer located in the instrument cluster. You can determine if the sensor is in failure by examining the continuity of the sensor to the tachometer. Also, you can examine the continuity between pins T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]) and between pin T6a/1 as well as pin T26a/12. You should detect a resistance of approximately 1000 ohms between these points. This part is common across the replacement audi keys 80-100-200-RS2 range, beginning with the 1985 MC and up to the 1997 UrS AN and the 1995 RS2 DU So, you may find them in wrecking yards.