The No. #1 Question That Everyone In Audi G28 Should Be Able To Answer
The No. #1 Question That Everyone In Audi G28 Should Be Able To Answer
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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 located near the transmission's edge just above the flywheel gear. It transmits a signal 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, directly above the flywheel ring. This sensor sends a signal via the grey wire to pin T55/49. The ECU utilizes this information to regulate boost and fuel. It also sends signals to the G5 tachometer in the instrument cluster.
The sensor is used as a reference point to connect with the G40 Camshaft Position Sensor. The ecu needs to be aware of when the crankshaft has reached TDC and also the location of the camshaft to trigger the spark and injectors.
If this sensor fails when it fails, the ECU will display a P00160 error message. This indicates that the Crank Shaft is out of sync with the Intake Camshaft. It could also indicate an issue with the chain or a jumpy chain link in the upper chain. The code will not appear without the additional information supplied by other sensors (G4 or G40).
Testing is a bit challenging because there are two connector pins and they have different functions but the most effective method of testing it is to measure the resistance between the sensor and the ECU. When the sensor is fully operational, it should be reading around 1000 ohms. Look for signs of coolant or oil in the connector bay if you have issues with this component.
2. Injectors
Yesterday, when accelerating from highway paytoll at maximum speed, i noticed a huge reduction in power. It was like the engine was running out of gas. Or my injectors weren't 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 three that have gazoline pop right out. The 4th one stays closed. I inspected the ground connection on ECU pins 14/55,30/55 and 48/55 I get zero Ohm. So i assume the problem is elsewhere.
I also tried to reset the PID with no success. The car will start when the G28 is unplugged, and it runs fine with audi tt keys the G28 plugged in. However, the intermittent misfire problem persists at higher RPM. The coolant sensor (G62), even when unplugged, still shows a temperature of -49c. I also noticed that the oil pressure gauge in the cockpit is showing 2 bar, whereas the actual pressure is 0.0 when i rev the engine.
I'm not certain what to do, but i believe that i've completely ruled out all other possibilities. I'm worried that i might have missed something. If anyone has any suggestions, please chime in! TIA!
3. Fuel Pump
The fuel more info pump in the g28 gets a signal from the RPM sensor. The GM-style transmitter is identical to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. You can easily find an extra in a wrecking shop or parts store. It is easy to test them - simply put your DMM into resistance mode and test the distance between pins 1 and 2 (with the bump at the connector's end facing upwards). 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 in order to make a decision about timing of the fuel injectors, etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these sensors go bad you will get codes on the diagnostic scanner which could cause engine shut down.
A malfunctioning G28 sensor could cause an inaccurate speed counter for your gearbox or a gearbox that shifts faster than normal, and/or a misfire while in gear. If you have any of these issues, it is likely your sensor is deteriorating and should be replaced. The good thing is that they are very cheap and readily available, especially if you're looking at the Bosch sensor, like ours. Alternatively, the GM version of this unit is also a good option.
5. Tachometer
A faulty engine speed sensor could be a cause for numerous issues with your vehicle. It is a crucial part of the Audi's transmission as it sends information to the ECU about how fast or slow the vehicle's crankshaft is spinning. When this sensor fails, it can disrupt the performance of the transmission as well as the other car's components.
The G5 engine here speed sensor is situated on the outside of the transmission above the flywheel ring gear and transmits a signal to the ECU at pin T55/49 through an uncolored wire. The ECU utilizes this click here signal to regulate fuel and boost, and also timig. It also transmits it to the G5 Tachometer in instrument cluster. You can check the sensor for failure by checking continuity between it and the tachometer. You can also check continuity between ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. You should observe approximately 1000 ohms of resistance between here these two points. This is a typical component across the Audi 80 100 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU so good ones might be availble in wrecking yards.