The No. One Question That Everyone In Audi G28 Needs To Know How To Answer
The No. One Question That Everyone In Audi G28 Needs To Know How To Answer
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How to Replace an Audi G28 Engine Speed Sensor
In this video, Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. This sensor is located on the outside of the transmission over the flywheel gear. It sends a message to the ECU via an uncolored wire T55/49, then to the tachometer located on 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 an electrical signal to ECU pin T55/49 through a grey wire. The ECU utilizes this information to regulate the amount of fuel and boost. It also sends an alert 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 know when the crankshaft is TDC and where the camshaft is so it can activate spark and injectors according to the situation.
If this sensor fails, the ECU will display a P00160 error code. This indicates that the Crank Shaft is out of line with the Intake Camshaft. It could also indicate a chain stretch or a jumpy chain link in the upper timing chain. However the code will not be displayed on its own without additional information from other sensors (G4 and G40).
Testing is a bit tricky because there are two connector pins and they perform different functions but the best method of testing it is by measuring resistance between the sensor and the ECU. It should read approximately 1000 ohms when it is at full operation. Check for evidence of coolant or oil in the connector bay if you have issues with this component.
2. Injectors
Yesterday accelerating full speed from highway paytoll, I experienced massive power loss like the engine is out of gas or the injectors are not firing anymore. In the morning, i removed the spark plugs. Three were drenched with gazoline the 4th one was dry. I put tissue over each injector hole, and when I start the engine with no sparks, the three with gazoline jump right out. The 4th one stays shut. I tried to test the ground connections of ECU pins 14,30 and 48/55. I found zero ohm. I assume that the problem is somewhere else.
I also tried to reset the PID without success. The car will start when the G28 is unplugged, and it works fine when the G28 plugged in. However, the intermittent misfire problem continues to occur 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 when the actual pressure is 0.
I don't know what to do. I think I've eliminated everything else. I'm concerned that i may have missed something. Let me know If you have any suggestions! TIA!
3. Fuel Pump
The fuel pump of the g28 receives a signal from the RPM sensor. The GM-style sensor is identical to website the G4 and they both work in the 80, 100, 200, UrS and RS2 cars which is why you can easily locate one at a wrecking yard or in a local parts store. It is simple to test them - simply switch your DMM into resistance mode and test 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 have an ECU that must know the speed and position get more info of the crankshaft in order to make decisions regarding timing of the fuel injector, for website example. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If you have a problem with either one of these, the diagnostic scanner will show the codes that could trigger an engine shut down.
The signs of a malfunctioning G28 sensor include an inaccurate rev counter for the gearbox, gears click here shifting quicker than normal and/or misfiring when you're in gear. If you experience any of these issues it is most likely that your sensor is deteriorating and needs replacing. The good thing is that they check here are very cheap and readily available, especially if you're looking at a Bosch unit which is what we have. Alternately, the GM version of this component is also a good option.
5. Tachometer
A faulty engine speed sensor could be the cause of numerous problems in your vehicle. It's a crucial component of the transmission of your Audi, as it transmits information to the ECU regarding how fast or slowly the engine is turning. This sensor can cause the transmission to malfunction and other car components to be affected.
The G5 engine speed sensor is located on the edge of the transmission just above the flywheel ring gear and sends a signal directly to the ECU at pin T55/49, via a grey wire. 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 test 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 via pin T6a/1 (trace [79trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. You should observe approximately 1000 ohms of resistance between those two pins. This is a typical part that is found across the Audi 80, 100, 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU, so the best ones could be available in wrecking yards.