Undisputed Proof You Need Audi G28
Undisputed Proof You Need Audi G28
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How to Replace an Audi G28 Engine Speed Sensor
In this video, Charles the humble mechanic demonstrates how to replace the G28 engine speed sensor. This sensor is situated near the transmission's edge over the flywheel gear. It transmits a signal to the ECU via an uncolored wire (T55/49) and then to the tachometer within the instrument cluster.
1. Engine Speed Sensor
Located on the edge of the transmission, above the flywheel ring gear G28 Engine Speed Sensor sends a signal to ECU pin T55/49 using a grey wire. The ECU then uses this information to control the boost, fuel, and timig. It also sends signals to the G5 tachometer in the instrument cluster.
The sensor serves as a reference to correlate with the G40 Camshaft Position Sensor. The ecu must be aware when the crankshaft is TDC and where the camshaft is so it can trigger spark and injectors in the right way.
If this sensor fails, the ECU will show the P00160 error, which means 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 since there are two connector pins, and they serve different purposes but the most effective method to test it is to measure the resistance between the sensor and the ECU. When the sensor is functional, it should read around 1000 ohms. If you are having problems with this sensor, look for signs of oil or coolant in the connector bay.
2. Injectors
Yesterday, as i was accelerating off the highway paytoll at full speed I noticed a significant drop in power. It was as if the engine had run out of gas. Or, my injectors were not firing. This morning i pull out the spark plugs. Three were drenched in gazoline, the fourth was dry. When I start the engine with no sparks, I put a piece of tissue on top of each injector hole and the 3 that were drenched in gazoline leap out, however the 4th one stays shut. I checked the ground connection of ECU pins 14,30 and 48/55. I got zero ohm. So i assume the problem is in another place.
I also tried to reset PID but without success. The car is able to start when the G28 is disconnected and runs fine when it is connected but it still has the intermittent misfire issue at higher RPM. The coolant sensor (G62) even if it is not plugged in, shows a temperature of -49c. Also, i noticed that more info the gauge for oil pressure in the cockpit is showing 2 bar when the actual pressure is 0.0 if i crank up the engine.
I'm not sure what to do. I feel like i've pretty much ruled everything else out. But i'm worried that i might have missed something. If anyone has suggestions, please let me know! TIA!
3. Fuel Pump
The fuel pump in the g28 gets a signal from the RPM sensor. The check here GM-style sender is the same as the G4 and both function in the 80 100, website 200, UrS and click here RS2 cars so you can easily find one at a wrecking yard or from a parts store. It is easy to test them - simply switch your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump at the connector end facing upwards). They must be infinite Ohms.
4. ECU
Our 20vt turbo (3B AAN, ABY, and ADU) engines are equipped with an ECU that must know the speed and position of the crankshaft to make a decision about fuel injector timing etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you are experiencing issues with either of these, the diagnostic scanner will show codes that could cause the engine shutting down.
Some of the symptoms of a malfunctioning G28 sensor include an inaccurate rev counter for the gearbox, gears shifting quicker than normal and/or misfiring when you are in gear. If you are experiencing any of these problems, it is likely your sensor is failing and needs replacing. The good thing is that they are very cheap and easily accessible particularly when you're looking at the Bosch unit like ours. Alternatively, GM's version of this component is an excellent choice.
5. Tachometer
A malfunctioning engine speed sensor could be the cause of a slew of problems in your car. It is a crucial part of your Audi's transmission, because it communicates to the ECU about how fast or slow the vehicle's crankshaft is rotating. When this sensor fails, it can disrupt the performance of the transmission as well as the rest of the car's components.
The G5 engine speed sensor is located on the outside of the transmission just above the flywheel ring gear. It transmits a signal to the ECU at pin T55/49 via an uncolored wire. The ECU is then able to process this signal to regulate the flow of fuel, timig and boost as well as sends it on to the G5 tachometer in the instrument cluster. You can test the sensor for failure by checking continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. You should audi a1 key replacement see a resistance of approximately 1000 ohms in these areas. This is a standard part 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 might be availble in wrecking yards.