Your Worst Nightmare About Audi G28 It's Coming To Life

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. This sensor is situated near the transmission's edge just above the flywheel gear. It sends a signal to the ECU via the grey wire (T55/49) and then to the tachometer located in the instrument cluster.

1. Engine Speed Sensor

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

The sensor is used to link 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 accordingly.

If this sensor fails when it fails, the ECU will display an error code P00160. This indicates that the Crank Shaft is out of sync with the Intake Camshaft. It could also indicate the possibility of a chain stretch or jumpy chain link in the upper chain. 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 connector pins and they serve different purposes but the most effective way to test it is by measuring resistance between the sensor and the ECU. It should read about 1000 ohms when it is in full operation. If you're having issues with this component, look for evidence of oil or coolant in the connector bay.

2. Injectors

Yesterday, when i was accelerating to the fullest speed from highway paytoll i had an abrupt drop in power like the engine is out of gas or injectors are not firing at all. I took out the spark plugs this morning, 3 were soaked in gasoline, and the 4th was dry. I put a piece of tissue over each injector hole, and when I start the engine without sparks, the 3 that have gazoline pop right out. The fourth one remains shut. I checked the ground connection on ECU pins 14/55, 30/55 and 48/55. I get 0ohm. I think the issue is elsewhere.

I also tried to reset the PID but without success. The car will start when the G28 is unplugged, and it runs fine with the G28 connected. However the intermittent misfire issue persists at higher RPM. The temperature sensor for coolant (G62) shows website the wrong temperature value of -49c, even if I unplug it. I also noticed that the oil gauge in the cockpit shows 2 bar but the actual pressure is 0.

I'm not sure what to do. I believe that I've eliminated everything else. I'm afraid i may have missed something. Please let me know if you have any ideas! TIA!

3. Fuel Pump

The fuel pump in the g28 is activated get more info by a signal sent from the RPM sensor. The GM-style transmitter is the same as the G4 and both are replacement audi key used in the 80, 100 200, UrS and RS2 cars so you can easily find one at a wrecking yard or in a local parts store. It is easy to test them - just switch your DMM into resistance mode and test the distance between pins 1 and 2 (with the bump on the connector's edge facing upwards). They must be infinite Ohms.

4. ECU

The ECU in our 20vt turbo (3B AAN ABY ADU) engines requires to know the position and speed of the crankshaft to determine timing of the audi key replacement near me fuel injector, etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you have a problem with either one of these, the diagnostic scanner will display the codes that could trigger the engine shutting down.

A failing G28 sensor could result in an inaccurate gearbox speed counter or a gearbox that shifts more quickly than normal, and/or an unfire when in the gear. It is probable that your sensor is failing and needs to be replaced if you notice any of these symptoms. The good news is they are very cheap and easily accessible, especially when you're looking at a Bosch sensor, which is what we have. Alternatively, GM's version of this part would be a good option.

5. Tachometer

A failing engine speed sensor could be the reason behind many problems in your car. It's an essential component of the transmission in your Audi since it sends information to the ECU replacement key for audi a3 regarding how fast or slowly the car's engine is turning. When this sensor fails, it will cause problems for the transmission as well as the rest of the car's components.

The G5 engine speed sensor is located at the edge of the transmission just above the flywheel ring gear and sends a signal to the ECU at pin T55/49 through a grey wire. The ECU uses this signal to regulate the flow of fuel and boost as well as timig. It also relays it to the G5 Tachometer located 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 [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 standard part across the Audi 80 100, 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU so good ones might be availble in wrecking yards.