Why Audi G28 Doesn't Matter To Anyone

How to Replace an audi car key replacement G28 Engine Speed Sensor

Charles the Humble Technician shows how to replace audi key the G28 Engine Speed Sensor. The sensor is located near the transmission's edge, above 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 grey wire is located at the edges of the transmission, directly above the flywheel ring. This sensor sends signals through the grey wire to pin T55/49. The ECU then uses this information to control fuel, timig and boost. It also sends an alert to the G5 Tachometer within the instrument cluster.

The sensor is used as a reference for comparing 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 to function, the ECU will display a P00160 error code. This means that the Crank Shaft is not in sync with the Intake Camshaft. It could also be a sign of the possibility of a chain stretch or jump in the chain link of the upper chain. However, the code won't appear on its own, without additional information from other sensors (G4 and G40).

It can be a bit difficult to test as there are different pins on the connector and each one has different functions. The best way to do it is to measure the resistance between the ECU and the sensor. It should read around 1000 ohms when it is at full operation. Look for signs of coolant, or oil in the connector bay if you have issues with this component.

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 any more. In the morning, i removed the spark plugs, three were soaked with gazoline and the fourth was dry. I put tissue over each injector hole and when I start the engine without sparks, the 3 that have gazoline pop right out. The 4th one stays shut. I tested the ground connection of ECU pins 14,30, and 48/55. I got zero ohm. I assume that the problem is somewhere else.

I also tried to reset PID without success. The car will start when the G28 is disconnected, but it runs fine with the G28 plugged in. However, the intermittent misfire problem continues to occur at higher RPM. The coolant sensor (G62), even when it is unplugged, shows an ice temperature of -49c. Also i noticed that the gauge for oil pressure in the cockpit shows 2 bar when the actual pressure is 0.0 if i crank up the engine.

I don't know what to do. I feel like i've pretty much ruled everything else out. I'm worried that i might have missed something. Let me know If you have any suggestions! TIA!

3. Fuel Pump

The fuel pump in the g28 receives signals from the RPM sensor. The GM-style sender is the same as the G4 and both are 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 simple to test them - simply switch your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump at the connector end facing upwards). They must be infinite Ohms.

4. ECU

The ECU of our 20vt turbo (3B AAN ABY) engines must know the speed and position of the crankshaft in order to make a decision about timing of fuel injectors, etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If you have a problem with either one of these, the diagnostic scanner will display codes that could cause an engine shut down.

The signs of a failed G28 sensor are an inaccurate gearbox rev counter and gears that shift faster than normal and/or misfiring when in gear. It is possible that the sensor is failing and requires to be replaced if you encounter any of these symptoms. The good news is they are quite affordable and easily accessible particularly if you're looking at the Bosch unit which is what we have. Alternatively, GM's version of this component is an excellent choice.

5. Tachometer

A malfunctioning engine sensor can cause a myriad of issues in your vehicle. It is a crucial part of your Audi's transmission, because it communicates to the ECU about how fast or slow the car's crankshaft is spinning. This sensor could cause the transmission to malfunction and other components in the car to be affected.

The G5 engine speed sensor is located on the outside of the transmission just above the flywheel ring gear. It sends a signal directly to the ECU at pin T55/49 via a grey wire. The ECU then uses and processes this signal to control fuel, Audi New key timig, and boost and then transmitting it to the G5 tachometer inside the instrument cluster. You can check the sensor for failure by examining the continuity between it and the tachometer. You can also check continuity between ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. You should see an average resistance of 1000 ohms in these areas. This is the same across the Audi New key 80-100-200-RS2 model, ranging from the 1985 MC all the way up to the 1997 UrS AN and 1995 RS2 Du So, you may find them in wrecking yards.