How to Replace an replacement key Audi G28 Engine Speed Sensor

Charles the Humble Technician teaches how to replace the G28 Engine Speed Sensor. This sensor is situated on the outside of the transmission just above the flywheel gear. It sends a message to the ECU via an uncolored wire T55/49, then to the tachometer on the instrument cluster.

1. Engine Speed Sensor

The grey wire is located on the outside of the transmission, above the flywheel ring. The sensor sends signals through the grey wire to pin T55/49. The ECU then uses this information to control the boost, fuel, and timig. It also sends an indicator to the G5 Tachometer located in the instrument cluster.

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

If this sensor fails, the ECU will display a P00160 error message. This means that the Crank Shaft is out of alignment with the Intake Camshaft. It could also indicate an issue with the chain or a jumped chain link in the upper chain of timing. However the code will not appear on its own without additional information from other sensors (G4 and G40).

It can be a bit difficult to test because there are several connector Audi Tt Key Replacement pins, and they all have different functions. The best method for doing this is to measure the resistance between the ECU and the sensor. It should read around 1000 ohms when it is at full operation. Check for signs of coolant, or oil in the connector bay if there are problems with this part.

2. Injectors

Yesterday, while accelerating at full speed from the highway paytoll i had massive power loss like the engine is out of gas or the injectors are not firing at all. I took out the spark plugs this morning, three were soaked with gasoline and the fourth was unclean. When I crank the engine without sparks i put tissue on the top of each hole in the injector and the 3 drenched with gazoline pop out, but the 4th stay closed. I checked the ground connection of ECU pins 14,30 and 48/55. I got zero ohm. I assume that the problem is in another location.

I also tried to reset the PID but without success. The car will start when the G28 is disconnected, but it is running fine with the G28 connected. However, the intermittent misfire problem persists at higher RPM. The coolant sensor (G62), even when it is unplugged, shows an ice 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, but i feel i have pretty much eliminated everything else. I'm afraid i may have missed something. If anyone has suggestions, please share them! TIA!

3. Fuel Pump

The fuel pump on the g28 is activated by a signal sent from the RPM sensor. The GM-style sender is the same as the G4 and both function 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. It is simple to test them - just put your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump at the connector end facing up). They must be infinite ohms.

4. ECU

Our 20vt turbo (3B, AAN, ABY and ADU) engines have an ECU that has to be aware of the speed and position of the crankshaft to make decisions regarding fuel injector timing etc. In order to do this it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you have a problem with either of these sensors, the diagnostic scanner will display the codes that could trigger an engine shut down.

A malfunctioning G28 sensor could result in an inaccurate gearbox speed counter or a gearbox that shifts more quickly than normal, or a misfire while in the gear. It is probable that your sensor is failing and requires to be replaced if you encounter any of these signs. The good thing is that they are quite affordable and readily available, especially when you're looking at the Bosch model, like ours. You can also choose the GM version of this component is also a good choice.

5. Tachometer

A faulty engine speed sensor could be the cause of a slew of problems in your car. It's a crucial component of the transmission in your replacement audi a4 key since it sends information to the ECU on how fast or slowly the engine is spinning. This sensor could cause the transmission to malfunction and other components of the car to be affected.

The G5 engine speed sensor is situated on the edge of the transmission, above the flywheel ring gear. It sends a signal directly to the ECU at pin T55/49, via an uncolored wire. The ECU uses this signal to regulate the amount of fuel and boost, and also timig. It also transmits it to the G5 Tachometer inside the instrument cluster. You can check for sensor failure by checking continuity from the sensor to the tachometer. Also, you can 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 and pin T26a/12. You should observe approximately 1000 ohms of resistance between those two pins. This is the same across the replacement audi key 80-100-200-RS2 range, beginning with the 1985 MC and Car Key Replacement Audi up to the 1997 UrS AN and the 1995 RS2 DU You may also find them in wrecking yards.