Why Nobody Cares About Audi G28

How to Replace an Audi remote key G28 Engine Speed Sensor

In this video, Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. The sensor is situated near the edges of the transmission, above the flywheel ring gear. It transmits a signal to the ECU through a grey wire T55/49, then to the tachometer on the instrument cluster.

1. Engine Speed Sensor

The grey wire is located on the edge of 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 a signal to the G5 Tachometer located in the instrument cluster.

The sensor serves 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 located so that it can start spark and injectors accordingly.

If this sensor fails the ECU will show the P00160 error, which means the Crank Shaft and Intake Camshaft aren't in sync and possibly indicating chain stretch or a jumped link on the upper timing chain. The code won't appear without the additional information provided by other sensors (G4 or G40).

Testing can be a bit difficult as there are two different connector pins, and they perform different functions but the best method of testing it is to measure the resistance between the sensor and the ECU. It should read around 1000 ohms when the sensor is operating at its maximum. If you are having problems with this component, look for signs of coolant or oil in the connector bay.

2. Injectors

Yesterday accelerating full speed from highway paytoll, i experienced an abrupt drop in power like the engine is out of gas or injectors aren't firing any more. I pulled out the spark plugs this morning, three were soaked in gasoline, and the 4th was dry. When I start the engine with no sparks, I put a piece of tissue on top of each injector hole, the 3 drenched with gazoline pop out, but the 4th one stays closed. I tested the ground connection on ECU pins 14/55,30/55 and 48/55 i get 0ohm. I'm assuming the issue is somewhere else.

I also tried to reset the PID with no success. The car will start when the G28 is disconnected, but it is running fine with the G28 plugged in. However the intermittent misfire issue continues to occur at higher RPM. The coolant sensor (G62) even if it is not plugged in, shows a temperature of -49c. I also noticed that the oil gauge in the cockpit shows 2 bar when the actual pressure is zero.

I don't know what to do. I think I've all other possibilities out. However, i'm afraid 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 from the RPM sensor. The GM-style sender 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 junkyard or in a local parts store. Testing them is easy - put your DMM in resistance mode and service measure the resistance between pins 1 (with the bump on the connector's end up) and 2 (2nd from left on the black connector's end). They should be infinite Ohms.

4. ECU

The ECU of our 20vt turbo (3B AAN ABY) engines needs to be aware of the position and speed 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 accomplish this. If you are experiencing issues with either one of these, the diagnostic scanner will show codes that could cause an engine shutdown.

Some of the symptoms of a failed G28 sensor nearest are an inaccurate rev counter in the gearbox, gears shifting quicker than normal and/or a misfire when you are in gear. It is likely that the sensor is failing and needs to be replaced if you encounter any of these signs. They're inexpensive and easy to locate, especially in the case of an Bosch model like ours. You can also choose the GM version of this unit is also a good choice.

5. Tachometer

A malfunctioning engine speed sensor could be the cause of a slew of issues in your replacement audi car key. It's an essential component of the audi replacement key cost's transmission since it relays information to the ECU about how fast or slow the car's crankshaft is rotating. This sensor could cause the transmission to fail and other components in the car to be affected.

The G5 engine speed sensor is located on the outside of the transmission, above the flywheel ring gear and sends a signal to the ECU at pin T55/49 through an uncolored wire. The ECU uses this signal to control the amount of fuel and boost, and also to timigrate. It also relays it to the G5 Tachometer inside the instrument cluster. You can test the sensor for failure by examining the continuity between it and the tachometer, between ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. It should show around 1000 ohms of resistance between those two pins. This is a common part that is found across the audi tt key fob not working 80, 100 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU, so the best parts could be found in wrecking yards.