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

In this video, Charles the humble mechanic demonstrates 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 the ECU via an uncolored wire (T55/49) which is then sent to the tachometer located in the instrument cluster.

1. Engine Speed Sensor

Located on the edge of the transmission, above the flywheel ring gear, the G28 Engine Speed Sensor sends an electrical signal to ECU pin T55/49 via a grey wire. The ECU then uses this information to control fuel, timig and boost. It also sends an alert to the G5 Tachometer located in the instrument cluster.

The sensor is used to link with the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft has reached TDC and also the position of the camshaft, to trigger the spark and injectors.

If this sensor fails the ECU will throw the P00160 error, which means the Crank Shaft and Intake Camshaft are not in sync and could indicate the chain is stretched or a jump link on the upper chain of timing. The code will not appear without the additional information supplied by other sensors (G4 or G40).

Testing is a bit challenging since there are two connector pins, and they perform different functions but the best method of testing it is by measuring resistance between the sensor and the ECU. If the sensor is operational, it should be reading approximately 1000 ohms. Check for signs of coolant, or oil in the connector bay if you have issues with this part.

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 running out of gas or the injectors are not firing any more. I pulled out the spark plugs this morning and found that 3 were soaked with gasoline and the fourth was dry. I placed a tissue over each hole in the injector and when I turn the engine on without sparks, the 3 that have gazoline pop right out. The 4th one remains shut. I checked the ground connection of ECU pins 14,30 and 48/55. I found zero ohm. So i assume the problem is somewhere else.

I also tried to reset the PID without success. The car is able to start when the G28 is unplugged and it runs perfectly when it is connected however it has the intermittent misfire issue at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature of -49c even when i unplug it. Also i noticed that the oil pressure gauge in the cockpit shows 2 bar when the actual pressure is 0.0 when i rev the engine.

I'm not sure what to do, as i believe that i've completely ruled out all other possibilities. But i'm worried that I may have missed something. If anyone has suggestions, please let me know! TIA!

3. Fuel Pump

The fuel pump in the g28 is activated by a signal by the RPM sensor. The GM-style transmitter is identical to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. You can easily locate a spare in a wrecking shop or parts store. Testing them is easy to do - just put your DMM in resistance mode and take measurements between pins 1 (with the bump on the connector's side up) and 2 (2nd from left on the black end of the connector). They must be infinite Ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY, and ADU) engines have an ECU that must know the position and speed of the crankshaft to make decisions about timing of the fuel injectors, etc. To accomplish this, it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you encounter a problem with either of these, the diagnostic scanner will show codes that could lead to an engine shut down.

A failing G28 sensor Audi key replacement cost could result in an inaccurate speed counter for the gearbox and a gearbox which shifts faster than normal, and/or an unfire when in gear. If you experience any of these issues it is likely your sensor is failing and needs replacing. The good news is that they are very cheap and readily available particularly when you're looking at a Bosch sensor, which is what ours are. You can also choose the GM version of this part is also a great option.

5. Tachometer

A failing engine sensor could cause a number of problems within your vehicle. It's an essential component of the audi keys's transmission as it sends information to the ECU about how the car's crankshaft is turning. If this sensor fails, it could cause problems for the transmission and the other car's components.

The G5 engine speed sensor is located at the edge of the transmission, above the flywheel ring gear and sends a signal to the ECU at pin T55/49, via a grey wire. The ECU then uses and processes the signal to control the flow of fuel, Audi Key replacement cost timig and boost and then transmitting it to the G5 Tachometer located in the instrument cluster. You can determine if the sensor is in failure by examining the continuity of 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 [79trace [79]), and between pin T6a/1 as well as pin T26a/12. There should be an average resistance of 1000 ohms between these two points. This is a standard part that is found across the audi q3 key 80, 100, 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU so good parts could be found in wrecking yards.