20 Myths About Audi G28: Dispelled

How to Replace an Audi Replacement Key Cost Uk 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 message to the ECU through a grey wire T55/49, then to the tachometer in the instrument cluster.

1. Engine Speed Sensor

The grey wire is situated at the edges of the transmission, directly above the flywheel ring. The sensor sends a signal via the grey wire to pin T55/49. The ECU utilizes this information to regulate boost and fuel. 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 where the camshaft is so it can activate spark and injectors accordingly.

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, possibly indicating the chain is stretched or a jump link on the upper chain of timing. However, the code won't be displayed on its own without additional information from other sensors (G4 and G40).

Testing is a bit challenging since there are two connector pins and they have different functions however the best way to test it is to measure resistance between the sensor and the ECU. It should read approximately 1000 ohms when it is operating at its maximum. Examine for signs of coolant or oil in the connector bay if there are issues with this part.

2. Injectors

Yesterday accelerating full speed from highway paytoll i had an abrupt drop in power like the engine is running out of gas or the injectors aren't firing at all. I took out the spark plugs this morning and found that 3 were drenched in gasoline and the fourth was unclean. I placed a tissue over each injector hole, and when i start the engine with no sparks, the three with gazoline jump out. The 4th one remains closed. I tested the ground connection of ECU pins 14,30, and 48/55. I found zero ohm. I'm assuming that the issue is in another location.

I also tried to reset the PID without success. The car can start if the G28 is unplugged and runs fine when it is plugged in however it is experiencing intermittent misfires at higher RPM. The temperature sensor for coolant (G62) shows the wrong temp value -49c, even if I unplug it. Also, i noticed that the oil pressure gauge in the cockpit is showing 2 bar while the actual pressure is 0.0 if i crank up the engine.

I don't know what to do. I believe that I've all other possibilities out. I'm concerned that i may have missed something. If anyone has any ideas please let me know! TIA!

3. Fuel Pump

The fuel pump on the g28 is activated by a signal sent by the RPM sensor. The GM-style sender is the same as the G4 and both are used in the 80 100, Spare Audi Key 200, UrS and RS2 cars which is why you can easily locate one at a junkyard or at a parts store. It is easy 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's end facing upwards). They should be infinite Ohms.

4. ECU

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

Some of the symptoms of a malfunctioning G28 sensor include an inaccurate rev counter in the gearbox, gears shifting quicker than normal and/or a misfire when you are in gear. It is probable that the sensor is failing and requires to be replaced if you encounter any of these symptoms. They're inexpensive and easy to locate especially when they're a Bosch unit like ours. You can also choose the GM version of this part is also a good option.

5. Tachometer

A faulty engine speed sensor Service could be the reason behind numerous issues in your car. It is a crucial part of the replacement audi key fob's transmission as it sends information to the ECU about how fast or slow the vehicle's crankshaft is spinning. If this sensor fails, it could affect the performance of the transmission, as well as the rest of the car's components.

The G5 engine sensor is located at the outskirts of the transmission, over the flywheel ring. It transmits an electrical signal through gray wire to ECU pin T55/49. The ECU utilizes this signal to control the amount of fuel and boost, and also to timigrate. It also transmits it to the G5 Tachometer inside 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 as well as pin T26a/12. There should be the resistance to be around 1000 ohms in these areas. This is a typical part that is found across the audi spare keys 80 100 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU. Good ones might be availble in wrecking yards.