25 Surprising Facts About Audi G28
25 Surprising Facts About Audi G28
Blog Article
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 at the top of the transmission above the flywheel ring gear. It sends a signal to the ECU via a grey wire (T55/49) which is then sent 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 via 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 in instrument cluster.
The sensor is used to correlate the G40 Camshaft position Sensor. The ecu must be aware when the crankshaft is TDC and the location of the camshaft so it can start spark and injectors accordingly.
If this sensor fails, the ECU will display a P00160 error message. This indicates that the Crank Shaft is not in line with the Intake Camshaft. It could also be a sign of an issue with the chain or a jumped chain link in the upper chain. However the code will not appear on its own without additional information from other sensors (G4 and G40).
It's a bit tricky to test as there are various pins on the connector and each has its own functions. The best method for doing this is by measuring the resistance between the ECU and the sensor. It should read approximately 1000 ohms when it is operating at its maximum. Examine for signs of coolant or oil in the connector bay if you have issues with this part.
2. Injectors
Yesterday, while accelerating from the highway paytoll at maximum speed I noticed a significant reduction in power. It was as if the engine was running out of gas. Or my injectors weren't firing. I pulled out the spark plugs this morning, three were drenched in gasoline and the fourth was unclean. When I crank the engine without sparks i put tissue on the top of each hole in the injector, the 3 drenched with gazoline pop out, but the 4th stay shut. I tested the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ i get 0ohm. I assume that the problem is elsewhere.
I also tried to reset the PID but without success. The car will start when the G28 is disconnected, but it is running fine with the G28 plugged in. However, the intermittent misfire problem persists at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature of that is -49c even after unplugging it. I also noticed that the oil gauge in the cockpit shows 2 bars but the actual pressure is 0.
I'm not sure what to do. I believe that I've ruled everything else out. But i'm worried that i might have missed something. Let me know should you have any suggestions! TIA!
3. Fuel Pump
The fuel pump in the g28 is activated by a signal sent by the RPM sensor. The GM-style sender is the same as the G4 and both function in the 80 100 200, UrS and RS2 cars which is why you can easily locate one at a salvage yard or at a parts store. Testing them is easy to do - just put your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector's click here side up) and 2 (2nd from the left on the black connector's end). They should 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 about fuel injector timing etc. It get more info uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If either of these goes website bad you will get codes on the diagnostic scanner that could cause engine shut down.
A failing G28 sensor could cause an inaccurate speed counter for the gearbox or a gearbox that shifts faster than normal, and/or a misfire while in gear. It is probable that the sensor is failing and needs to be replaced if you encounter any of these signs. They are cheap and easy-to-find particularly in the case of a check here Bosch unit like ours. Alternatively, the GM version of this unit is also a good choice.
5. Tachometer
A faulty engine speed sensor could be the reason behind a slew of problems in your vehicle. It's an essential component of the transmission in your Audi, as it transmits information to the ECU regarding how fast or check here slowly the car's engine is spinning. If the sensor fails, it could affect the performance of the transmission, as well as the rest of the car's components.
The G5 engine speed sensor is located at the outside of the transmission just above the flywheel ring gear. It sends a signal directly to the ECU at pin T55/49 through an uncolored wire. The ECU is then able to process the signal to control the flow of fuel, timig and boost, and also sends it on to the G5 Tachometer located in the instrument cluster. You can test for sensor failure by examining the continuity from the sensor to the tachometer. You can also verify 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. You should see around 1000 ohms of resistance between those 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 may find good ones in wrecking yards.