How to Replace an
audi lost key G28 Engine Speed Sensor
Charles the Humble Technician shows you how to replace the G28 Engine Speed Sensor. This sensor is located on the edge of the transmission just above the flywheel ring gear. It sends a signal to the ECU via an uncolored wire (T55/49) which is then sent to the tachometer within the instrument cluster.
1. Engine Speed Sensor
The grey wire is situated on the outside of the transmission, just above the flywheel ring. This sensor sends a signal via the grey wire to pin T55/49. The ECU then uses this information to control the boost,
Replacement Audi Car Key fuel, and timig. It also sends signals to the G5 Tachometer located in the instrument cluster.
The sensor is used to link the G40 Camshaft position Sensor. The ecu needs to be aware of when the crankshaft has reached TDC, and the location of the camshaft to trigger the spark and injectors.
If this sensor fails, the ECU will throw a P00160 code which means the Crank Shaft and Intake Camshaft aren't in sync, possibly indicating the chain is stretched or a jump 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).
It is a little tricky to test as there are different pins on the connector and they all have different functions. The best way to do it is to measure the resistance between the ECU and the sensor. When the sensor is operational, it should be reading approximately 1000 ohms. If you are having problems with this component, look for evidence of coolant or oil in the connector bay.
2. Injectors
Yesterday accelerating full speed from highway paytoll i had massive power loss like the engine is out of gas or the injectors aren't firing anymore. Today, i pulled out the spark plugs. Three were soaked with gazoline and the fourth was dry. I put tissue over each hole in the injector and when I start the engine with no sparks, the ones with gazoline jump right out. The 4th one stays closed. I checked the ground connection of ECU pins 14,30 and 48/55. I got 0ohm. I'm assuming that the issue is somewhere else.
I also tried to reset the PID with no success. The car will start when the G28 is unplugged, and it runs fine with the G28 connected. However, the intermittent misfire problem still occurs at higher RPM. The coolant sensor (G62), even when unplugged, still shows an ice temperature of -49c. Also, i noticed that the gauge for oil pressure in the cockpit is showing 2 bar, whereas the actual pressure is 0.0 if i crank up the engine.
I don't know what to do. I feel like i've pretty much eliminated everything else. I'm worried that i might have missed something. Let me know If you have any suggestions! TIA!
3. Fuel Pump
The fuel pump of the g28 gets a signal from the RPM sensor. The GM-style sender is identical to the G4 and both function in the 80 100 200, UrS and RS2 cars which is why you can easily locate one at a wrecking yard or at a parts store. It is simple to test them - simply switch 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 should 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 timing of the fuel injector, for example. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If either of these go wrong, you will receive codes on the diagnostic scanner which can lead to engine shutdown.
A malfunctioning G28 sensor could cause an inaccurate gearbox speed counter, a gearbox that shifts more quickly than normal, and/or a misfire while in gear. It is possible that the sensor is failing and needs to be replaced if you notice any of these signs. They're cheap and easy to find particularly when they're an Bosch sensor like ours. Alternately, the GM version of this unit is also a good option.
5. Tachometer
A damaged engine sensor could cause a variety of issues within your vehicle. It is an important part of the transmission of your Audi since it sends information to the ECU about how fast or slow the engine is turning. This sensor can cause the transmission to malfunction and other car components to be affected.
The G5 engine sensor is located at the edge of the transmission, over the flywheel ring. It transmits signals via gray wire to ECU pin T55/49. The ECU uses this signal to regulate the amount of fuel and boost, and also timig. It also transmits it to the G5 Tachometer located in the instrument cluster. You can test the sensor for failure by examining the continuity between it and the tachometer, between the ECU pin T55/49 and
Replacement Audi Car Key the instrument cluster connection to pin T6a/1 (trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. You should see around 1000 ohms of resistance between those points. This is a standard part that is found across the
replacement audi car key 80 100 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU so good ones might be availble in wrecking yards.
