How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician teaches how to replace the G28 Engine Speed Sensor. This sensor is located near the edges of the transmission, above the flywheel ring gear. It transmits a signal to the ECU through an uncolored wire T55/49, then to the tachometer in the instrument cluster.
1. Engine Speed Sensor
The sensor is located at the edge of the transmission just above the flywheel ring gear the G28 Engine Speed Sensor sends a signal to ECU pin T55/49 through an uncolored wire. The ECU utilizes this information to regulate fuel and boost. It also sends an indicator to the G5 Tachometer located in the instrument cluster.
The sensor serves as a reference for comparing with the G40 Camshaft Position Sensor. The ecu must be aware when the crankshaft is TDC and the location of the camshaft so it can trigger spark and injectors in the right way.
If this sensor fails, the ECU will show an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are out of sync and 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).
Testing is a bit challenging as there are two different connector pins and they have different functions but the most effective method to test it is by measuring resistance between the sensor and the ECU. If the sensor is operational, it should be reading approximately 1000 ohms. Look for signs of coolant, or oil in the connector bay if you have problems with this part.
2. Injectors
Yesterday, when accelerating from highway paytoll at a high speed I noticed a massive decrease in power. It was as if the engine had run out of gas. Or my injectors were not firing. In the morning, i removed the spark plugs. Three were drenched with gazoline the fourth one was dry. I put a piece of tissue over each injector hole and when i turn the engine on without sparks, the 3 with gazoline jump out. The fourth one remains closed. I tested the ground connection on ECU pins 14/55, 30/55 and 48/55. I get zero ohm. I assume that the problem is somewhere else.
I also tried to reset the PID with no success. The car is able to start when the G28 is disconnected and is running fine when it is connected however it has intermittent misfire issues at higher RPM. The coolant sensor (G62), even when unplugged, still shows a temperature of -49c. Also, i noticed that the gauge for oil pressure in the cockpit shows 2 bar while the actual pressure is 0.0 if i crank up the engine.
I don't know what to do. I believe that I've all other possibilities out. However, i'm afraid that I might have missed something. Please let me know should you have any suggestions! TIA!
3. Fuel Pump
The fuel pump of the g28 audi a4 spare key receives a signal from the RPM sensor. The GM-style sensor is identical to the G4 and both function in the 80, 100 200, UrS and RS2 cars so you can easily find one at a junkyard or from a parts store. It is easy to test them - simply put your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump at the connector's end facing replacement car key audi up). They must be infinite Ohms.
4. ECU
Our 20vt turbo (3B AAN, ABY and ADU) engines are equipped with an ECU that has to know the speed and position of the crankshaft in order to make decisions regarding timing of the fuel injector, for example. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If either of these sensors go badly, you will see codes on the diagnostic scanner that can cause the engine to shut down.
The signs of a failing G28 sensor audi spare keys are an inaccurate gearbox rev counter, gears shifting quicker than normal and/or a misfire when in gear. If you have any of these problems, it is likely your sensor is failing and needs replacing. They're inexpensive and easy to locate especially in the case of an Bosch model like ours. If you prefer, GM's version of this part would be a good option.
5. Tachometer
A malfunctioning engine speed sensor could be the cause of numerous issues in your vehicle. It's an essential component of the transmission of your Audi since it sends information to the ECU on how fast or slow the car's engine is spinning. If the sensor fails, it could disrupt the performance of the transmission, as well as the rest of the car's components.
The G5 engine speed sensor is situated on the edge of the transmission just above the flywheel ring gear. It transmits a signal to the ECU at pin T55/49 through a grey wire. The ECU uses this signal to control the amount of fuel and boost, and also timig. It also relays it to the G5 Tachometer in instrument cluster. You can determine if the sensor is in failure by examining the continuity from the sensor to the tachometer. Additionally, you can examine the continuity between pins T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]), and between pin T6a/1 as well as pin T26a/12. You should see an average resistance of 1000 ohms in these areas. This is a standard part that is found across the Audi 80, 100 200, UrS and RS2 range audi spare key replacement from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU so good parts could website be found in wrecking yards.