4 Dirty Little Details About Audi G28 And The Audi G28 Industry

How to Replace an Audi Spare Key Cost G28 Engine Speed Sensor

Charles the Humble Technician shows you how to replace the G28 Engine Speed Sensor. The sensor is located near the transmission's edge, above the flywheel gear. It transmits a signal to the ECU via the grey wire T55/49 and then to the tachometer in the instrument cluster.

1. Engine Speed Sensor

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

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

If this sensor fails the ECU will display an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are not in sync and could indicate chain stretch or a jumped link on the upper timing chain. The code will not appear without the additional information supplied by other sensors (G4 or G40).

It can be a bit difficult to test because there are different connector pins, and each has its own functions. The best way to do it is by measuring the resistance between the ECU and the sensor. It should read around 1000 ohms if the sensor is operating at its maximum. If you're experiencing issues with this sensor, look for signs of oil or coolant in the connector bay.

2. Injectors

Yesterday accelerating full speed from highway paytoll, I experienced an abrupt drop in power like the engine is running out of gas or injectors aren't firing anymore. This morning i pull out the spark plugs, three were soaked with gazoline and the 4th one was dry. When i crank the engine without sparks, i place a tissue on the top of each hole in the injector and the 3 that were drenched in gazoline jump out but the 4th stay shut. I tested the ground connection on ECU pins 14/55,30/55 and 48/55 i get zero ohm. So i assume the problem is somewhere else.

I also tried to reset the PID without success. The car can start if the G28 is not plugged in and it runs perfectly when it is connected however it has the intermittent misfire issue at higher RPM. The coolant sensor (G62) even when unplugged, still shows a temperature of -49c. 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 feel like i've pretty much ruled everything else out. I'm worried that i might have missed something. Please let me know should you have any suggestions! TIA!

3. Fuel Pump

The fuel pump of the g28 gets a signal from the RPM sensor. The GM-style sensor Audi Key Shell is the same as the G4 and both function in the 80, audi a3 key replacement 100, 200, UrS and RS2 cars which is why you can easily locate one at a salvage yard or at a parts store. It is simple to test them: simply switch your DMM into resistance mode and test the distance between pins 1 and 2 (with the bump on the connector's edge facing up). They should be infinite Ohms.

4. ECU

The ECU in our 20vt turbo (3B AAN ABY ADU) engines needs to be aware of the position and speed of the crankshaft to make decisions regarding timing of fuel injectors, etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these goes badly, you will see codes on the diagnostic scanner which can cause the engine to shut down.

The signs of a malfunctioning G28 sensor include an inaccurate rev counter in the gearbox and gears that shift faster than normal, and/or a misfire when you are in gear. If you are experiencing any of these issues, it is likely that your sensor is going bad and should be replaced. The good news is that they are quite affordable and readily available, especially if you're looking at an Bosch sensor, like ours. Alternatively, GM's version of this part is a good option.

5. Tachometer

A malfunctioning engine speed sensor could be the cause of a slew of issues with your car. It's a crucial component of the transmission of your new audi key because it relays information to the ECU regarding how fast or slowly the engine of the car is spinning. When this sensor fails, it will cause problems for the transmission, as well as the other car's components.

The G5 engine sensor is located at the edge of the transmission, just above the flywheel ring. It sends a signal via gray wire to ECU pin T55/49. The ECU uses this signal to control the flow of fuel and boost as well as timig. It also sends it to the G5 Tachometer in instrument cluster. You can check for sensor failure by checking continuity from the sensor to the tachometer. You can also 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. There should be an average resistance of 1000 ohms between these points. This is the same across the new audi key 80-100-200-RS2 range, from the 1985 MC all the way up to the 1997 UrS AN and the 1995 RS2 Du You may also find good ones in wrecking yards.