How to replace audi key an audi tt replacement Key G28 Engine Speed Sensor
Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. This sensor is situated on the outside of the transmission over the flywheel gear. It transmits a signal to the ECU through the grey wire T55/49 and then to the tachometer located on the instrument cluster.
1. Engine Speed Sensor
The grey wire is located on the edge of transmission, just above the flywheel ring. This sensor sends an electrical signal through the grey wire to pin T55/49. The ECU then uses this information to control the flow of fuel, timig and boost. It also sends an alert to the G5 Tachometer within the instrument cluster.
The sensor is used as a reference point to connect 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 trigger spark and injectors accordingly.
If this sensor fails, the ECU will show an error code P00160 which indicates that the Crank Shaft and Intake Camshaft aren’t in sync and possibly indicating chain stretch or a jumped link on the upper chain of timing. However the code will not appear on its own without additional information from other sensors (G4 and G40).
Testing is a bit challenging because there are two pins for the connector and they have different functions but the best method to test it is by measuring resistance between the sensor and the ECU. When the sensor is fully operational, it should be reading approximately 1000 ohms. If you’re experiencing issues with this component, look for evidence of oil or coolant in the connector bay.
2. Injectors
Yesterday, when i was accelerating to the fullest speed from highway paytoll, I experienced an abrupt drop in power like the engine is running out of gas or injectors are not firing at all. I pulled out the spark plugs this morning and found that 3 were soaked with gasoline and the 4th was dry. I placed a tissue over each injector hole and when I start the engine without sparks, the 3 that have gazoline pop right out. The 4th one remains shut. I checked the ground connection on ECU pins 14/55,30/55 and 48/55 I got 0ohm. I assume that the problem is in another location.
I also tried to reset PID but without success. The car will start when the G28 is disconnected, but it works fine when the G28 plugged in. However, the intermittent misfire problem still occurs at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature value of -49c even when i unplug it. Also, i noticed that the gauge for oil pressure in the cockpit shows 2 bar when the actual pressure is 0.0 if i crank up the engine.
I don’t know what to do. I think I’ve ruled everything else out. I’m worried that i might 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 transmitter functions similarly to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. You can easily locate the audi spare key in a salvage shop or parts store. It is easy to test them – simply switch your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump at the connector’s end facing upwards). They must be infinite ohms.
4. ECU
Our 20vt turbo (3B, AAN, ABY and ADU) engines have an ECU that must know the speed and position of the crankshaft in order to make decisions regarding timing of the fuel injectors, etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these go bad you will get codes on the diagnostic scanner which could cause engine shut down.
Some of the signs of a malfunctioning G28 sensor include an inaccurate rev counter in the gearbox the gears are shifting faster than normal and/or a misfire when you’re in gear. If you experience any of these issues it is likely that your sensor is failing and requires replacement. The good news is they are very cheap and easy to find, especially when you’re looking at a Bosch sensor, which is what we have. Alternatively, the GM version of this component is also a good option.
5. Tachometer
A faulty engine speed sensor could be the cause of many issues with your vehicle. It’s a crucial component of the transmission in your audi a4 replacement key since it sends information to the ECU regarding how fast or slowly the engine is turning. This sensor can cause the transmission to fail and other components in the audi car keys to be affected.
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 through an uncolored wire. The ECU then uses and processes the signal to control fuel, timig, and boost and then sends it on to the G5 Tachometer located in the instrument cluster. You can check the sensor for failure by examining the continuity between it and the tachometer, between ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. It should show around 1000 ohms of resistance between these two points. This is a common component across the audi keys replacement 80 100, 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU so good parts could be found in wrecking yards.