jeephip52

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. The sensor is located at the edge of transmission just above the flywheel gear. It sends a signal to the ECU via an uncolored wire (T55/49) and then to the tachometer in the instrument cluster. 1. Engine Speed Sensor The sensor is located at the edge of the transmission, above the flywheel ring gear the G28 Engine Speed Sensor sends an electrical signal to ECU pin T55/49 using the grey wire. The ECU then uses this information to control the flow of fuel, timig and boost. It also sends an indication to the G5 tachometer inside the instrument cluster. The sensor is used to link with the G40 Camshaft position Sensor. The ecu has to be aware of when the crankshaft has reached TDC and also the position of the camshaft, so that it can activate 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 alignment 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. However the code will not appear on its own, without additional information from other sensors (G4 and G40). Testing is a bit tricky as there are two different connector pins and they perform 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 approximately 1000 ohms. If you're experiencing issues with this part, check for evidence of coolant or oil in the connector bay. 2. Injectors Yesterday, while accelerating at full speed from the highway paytoll, i experienced massive power loss like the engine is running out of gas or injectors are not firing any more. I took out the spark plugs this morning, 3 were soaked with gasoline and the fourth was dry. When I start the engine with no sparks, I put a piece of tissue on the top of each of the injector holes and the 3 drenched with gazoline leap out, however the 4th stay shut. I checked the ground connection of ECU pins 14,30 and 48/55. I found 0ohm. I'm assuming the issue is elsewhere. replacement audi keys tried to reset PID without success. The car is able to start when the G28 is disconnected and is running fine when it is plugged in but it still has intermittent misfire issues at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature value of -49c, even if I unplug it. I also noticed that the oil gauge in the cockpit shows 2 bar while the actual pressure is 0. I'm not certain what to do, as i feel i have pretty much completely ruled out all other possibilities. I'm worried that i might 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 the same as the G4 and both function in the 80 100 200, UrS and RS2 cars so you can easily find one at a salvage yard or in a local parts store. Testing them is easy by putting your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector's end up) and 2 (2nd from the left on the black end of the connector). They must be infinite Ohms. 4. ECU Our 20vt turbo (3B AAN, ABY and ADU) engines have an ECU that needs to be aware of the speed and position of the crankshaft to make decisions regarding fuel injector timing etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If either of these sensors go wrong, you will receive codes on the diagnostic scanner which could cause engine shut down. Some of the signs of a malfunctioning G28 sensor are an inaccurate rev counter in the gearbox, gears shifting quicker than normal and/or misfiring when in gear. If you experience any of these problems, it is likely that your sensor is deteriorating and requires replacement. The good news is that they are very cheap and easily accessible particularly when you're looking at a Bosch model, which is what we have. Alternatively, GM's version of this part is a good option. 5. Tachometer A failing engine sensor could cause a variety of issues in your vehicle. It's a vital component of your Audi's transmission, as it sends information to the ECU about how fast or slow the car's crankshaft is turning. If the sensor fails, it could disrupt the performance of the transmission and the other car's components. The G5 engine speed sensor is situated on the edge of the transmission just above the flywheel ring gear. It transmits a signal to the ECU at pin T55/49 via a grey wire. The ECU then processes the signal to control fuel, timig, and boost as well as sends it on to the G5 tachometer inside the instrument cluster. You can test for sensor failure by checking continuity from the sensor to the tachometer. Also, you can check continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]), and between pin T6a/1 as well as pin T26a/12. It should show approximately 1000 ohms of resistance between these two points. This part is common across the Audi 80-100-200-RS2 model, ranging from the 1985 MC up to the 1997 UrS AN and the 1995 RS2 DU, so you might find them in wrecking yards.