How to Replace an Audi G28 Engine Speed Sensor

In this video Charles the humble mechanic demonstrates how to replace the G28 engine speed sensor. This sensor is located near the transmission's edge just above the flywheel gear. It sends a message to the ECU through the grey wire T55/49 and then to the tachometer in the instrument cluster.

1. Engine Speed Sensor

It is located on the outside of the transmission, above the flywheel ring gear, the G28 Engine Speed Sensor sends an electrical signal to ECU pin T55/49 through an uncolored wire. The ECU then uses this information to control the boost, fuel, and timig. It also sends a signal to the G5 tachometer in the instrument cluster.

The sensor serves as a reference point to connect with the G40 Camshaft Position Sensor. The ecu needs to know when the crankshaft is TDC and where the camshaft is so it can activate spark and injectors according to the situation.

If this sensor fails, the ECU will display an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are out of sync and could indicate the chain stretching or a jump link on the upper timing chain. However, the error code won't appear on its own, without additional information from other sensors (G4 and G40).

Testing can be a bit difficult as there are two different connector pins and they have different functions but the most effective method to test it is to measure resistance between the sensor and the ECU. When the sensor is fully operational, it should be reading around 1000 ohms. If you are having problems with this component, look for evidence of oil or coolant in the connector bay.

2. Injectors

Yesterday, while accelerating from the highway paytoll at full speed I noticed a massive reduction in power. It was as if the engine had run out of gas. Or my injectors were not firing. In the morning, i removed the spark plugs. Three were drenched with gazoline the fourth one was dry. When I crank the engine, there are no sparks, I put a piece of tissue on the top of each of the injector holes, the 3 drenched with gazoline jump out but the 4th stay closed. I tested the ground connection of ECU pins 14,30, and 48/55. I got 0ohm. So i assume the problem is somewhere else.

I also tried to reset PID without success. The car is able to start if the G28 is disconnected and is running fine when it is connected but it still is experiencing intermittent misfires at higher RPM. The coolant sensor (G62), even when unplugged, still shows a temperature of -49c. Also, i noticed that the gauge for oil pressure in the cockpit is showing 2 bar while the actual pressure is 0.0 when I crank up the engine.

I'm not sure what to do. I think I've ruled everything else out. But i am afraid I may have missed something. If anyone has any ideas please let me know! TIA!

3. Fuel Pump

The fuel pump in the g28 receives a signal from the RPM sensor. The GM-style sensor is the same as the G4 and they both work in the 80 100 200, UrS and RS2 cars which is why you can easily locate one at a salvage yard or in a local parts store. It is easy to test them - just put your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump on the connector's edge facing up). They must be infinite Ohms.

4. ECU

Our 20vt turbo (3B, AAN, ABY and ADU) engines have an ECU that has to know the position and speed of the crankshaft to make a decision about fuel injector timing etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve read more this. If you are experiencing issues with either one of these, the diagnostic scanner will show codes that could lead to the engine shutting down.

Some of the signs of a failed G28 sensor include an inaccurate rev counter in the gearbox, gears shifting quicker than normal and/or misfiring when in gear. If you experience any of these issues it is likely your sensor is going bad and needs replacing. The good news is they are very cheap and easy to find, especially if you're looking at the Bosch model, like ours. Alternately, the GM version of this component is also a great option.

5. Tachometer

A audi keys replacement faulty engine speed sensor could be the reason behind numerous issues in your vehicle. It's an essential component of the transmission in your Audi, as it transmits information to the ECU regarding how fast or slowly the car's read more engine is turning. This sensor can cause the transmission to fail and other components of the car to be affected.

The G5 engine sensor is located at the outskirts of transmission, above the flywheel ring. It transmits an electrical signal through a gray wire to the ECU pin T55/49. The ECU uses this signal to regulate fuel and boost, and also to timigrate. It also sends it to the G5 Tachometer inside the instrument cluster. You can check for sensor failure by examining the continuity of the sensor to the read more tachometer. Additionally, you can verify continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]), and between pin T6a/1 and pin T26a/12. You should see an average resistance of 1000 ohms in these areas. This is a common feature across the Audi 80-100-200-RS2 model, ranging from audi advanced key the 1985 MC up to the 1997 UrS An and 1995 RS2 Du So, you may find good ones in wrecking yards.