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 on the edge of the transmission, above the flywheel ring gear. It transmits a signal to the ECU via an uncolored wire T55/49, then to the tachometer located on the instrument cluster.
1. Engine Speed Sensor
It is located on the outside of the transmission, above the flywheel ring gear, the G28 Engine Speed Sensor sends a signal to ECU pin T55/49 via a grey wire. The ECU then utilizes this information to regulate the boost, fuel, and timig. It also sends signals 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 needs to know when the crankshaft is TDC and the location of the camshaft so it can trigger spark and injectors accordingly.
If this sensor fails when it fails, the ECU will display an error code P00160. This means that the Crank Shaft is not in sync with the Intake Camshaft. It could also be a sign of a chain stretch or a jumpy chain link in the upper chain of timing. The code won't show without the additional information provided by other sensors (G4 or G40).
It is a little tricky to test because there are several pins on the connector, and each has its own functions. The best way to do it is to measure the resistance between the ECU and the sensor. It should read about 1000 ohms when the sensor is operating at its maximum. Examine for signs of coolant or oil in the connector bay if you are experiencing issues with this component.
2. Injectors
Yesterday, as i was accelerating off the highway paytoll at a high speed I noticed a massive reduction in power. It was as if the engine was running out of gas. Or my injectors were not firing. This morning i pull out the spark plugs, three were drenched in gazoline, the fourth one was dry. When I start the engine without sparks, I put a piece of tissue on top of each injector hole, the 3 drenched with gazoline jump out but the 4th stay closed. I checked the ground connection of ECU pins 14,30, and 48/55. I got 0ohm. I'm assuming that the issue is in another location.
I also tried to reset the PID without success. The car is able to check here start if the G28 is disconnected and is running fine when it is plugged in, but still has the intermittent misfire issue at higher RPM. The coolant sensor (G62), even when it is unplugged, shows temperatures of -49c. I also noticed that the oil gauge in the cockpit shows 2 bar but the actual pressure is 0.
I don't know what to do. I believe that I've eliminated everything else. I'm worried click here that i might have missed something. Please 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 transmitter is identical to the G4 sender and works on the 80,100,200, UrS, and RS2 vehicles. You can easily locate a spare in a wrecking shop or a 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 end up) and 2 (2nd from left on the black end of the connector). They must be get more info infinite Ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY ADU) engines must know the position and speed the crankshaft to make decisions regarding timing of fuel injectors, etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these sensors go bad you will read more get codes on the diagnostic scanner which can lead to engine shutdown.
Some of the signs of a failing G28 sensor are an inaccurate rev counter in the gearbox the gears are shifting faster than normal and/or misfiring when in gear. It is likely that your sensor is failing and requires to be replaced if read more you notice any of these symptoms. The good thing is that they are quite affordable and easily accessible, especially in the case of the Bosch sensor, which is what we have. Alternately, GM's version this component is a good option.
5. Tachometer
A malfunctioning engine speed sensor could be the cause of a slew of issues with your vehicle. It's an essential component of the transmission of your Audi, as it transmits information to the ECU about how fast or slowly the car's engine is spinning. When this sensor fails, it will disrupt the performance of the transmission as well as the other car's components.
The G5 engine sensor is located at the edge of transmission, above the flywheel ring. It transmits a signal via a gray wire to the ECU pin T55/49. The ECU is then able to process this signal to regulate the flow of fuel, timig and boost, and also sends it on to the G5 Tachometer located in the instrument cluster. You can check for sensor failure by checking continuity from the sensor to the tachometer. Also, you can examine the continuity between pins 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 detect an average resistance of 1000 ohms between these two points. This is a typical part across the Audi 80 100 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU. Good ones might be availble in wrecking yards.