20 Myths About Audi G28: Dispelled
20 Myths About Audi G28: Dispelled
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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 outside of the transmission just above the flywheel gear. It transmits a signal to the ECU through the grey wire T55/49 and then to the tachometer in the instrument cluster.
1. Engine Speed Sensor
The grey wire is located on the outside of the transmission, just above the flywheel ring. The sensor transmits signals through the grey wire to pin T55/49. The ECU utilizes this information to control fuel and boost. It also sends a signal to the G5 tachometer inside the instrument cluster.
The sensor is used to correlate the G40 Camshaft position Sensor. The ecu has to know when the crankshaft reached TDC and also the location of the camshaft so that it can activate the spark and injectors.
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 timing chain. However, the error code won't appear on its own, without additional information from other sensors (G4 and G40).
Testing is a bit tricky because there are two pins for the connector and they serve different purposes however the best method of testing it is to measure the resistance between the sensor and the ECU. It should read around 1000 ohms when the sensor is operating at its maximum. If you are having problems with this component, look for evidence of oil or coolant in the connector bay.
2. Injectors
Yesterday, while accelerating from the highway paytoll at full speed I noticed a massive reduction in power. It was as if the engine had run out of gas. Or my injectors weren't firing. Today, i pulled out the spark plugs. Three were soaked with gazoline and the fourth was dry. I put tissue over each injector hole and when i start the engine without sparks, the ones with gazoline jump right out. The 4th one stays closed. I tested the ground connection on ECU pins 14/55, 30/55 and 48/55. I get zero ohm. I'm assuming the issue is somewhere else.
I also tried to reset the PID without success. The car will start when the G28 is unplugged, and it runs fine with the G28 connected. However replacement key for audi a3 the intermittent misfire issue continues to occur at higher RPM. The temperature sensor for coolant (G62) shows the wrong temp value -49c, even if I unplug it. Also, i noticed that the gauge for oil pressure in the cockpit is showing 2 bar when the actual pressure is 0.0 if i check here crank up the engine.
I'm not certain what to do, but i feel i have pretty much ruled out everything else. But i am afraid I may have missed something. If anyone has any ideas please share them! TIA!
3. Fuel Pump
The fuel pump in the g28 gets a signal from the RPM sensor. The GM-style transmitter is similar to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. It is easy to find a spare in a wrecking shop or a parts store. Testing them is easy by putting your DMM in resistance mode and measure between pins 1 (with the bump on the connector's side up) and 2 (2nd from the left on the black connector's side). They should be infinite Ohms.
4. ECU
Our 20vt check here turbo (3B AAN, ABY, and ADU) engines are equipped with an ECU that needs to know the position and speed of the crankshaft in order to make a decision about timing of the fuel injector, for example. In order to do this it uses 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 show the codes here that could trigger an engine shutdown.
A malfunctioning G28 sensor could cause an inaccurate speed counter for your gearbox, a gearbox that shifts faster than normal, and/or a misfire while in gear. It is possible that your sensor is failing and needs to be replaced if you experience any of these signs. The good news is they are very cheap and easy to find particularly if you're looking at an Bosch sensor, like audi replacement key uk ours. If you prefer, GM's version of this component is an option.
5. Tachometer
A malfunctioning engine speed sensor could be the reason behind a slew of issues with your vehicle. It's a crucial component of the transmission of your Audi, as it transmits information to the ECU on how fast or slowly the engine of the car is spinning. If this sensor fails, it can cause problems for the transmission as well as the rest of the car's components.
The G5 engine sensor is located near the edge of transmission, above the flywheel ring. It transmits a signal via an uncolored wire to the ECU pin T55/49. The ECU then processes this signal to control the flow of fuel, timig and boost, and also transmitting it to the G5 tachometer inside the instrument cluster. You can check the sensor for any failure by checking the continuity between it and the tachometer. You can also check continuity between ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. There should be an average resistance of 1000 ohms between these two points. This is a standard part that is found across the Audi 80, 100 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU, so the best ones could be available in wrecking yards.