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 edges of the transmission, above the flywheel ring gear. It sends a signal to the ECU via a grey wire (T55/49) and then to the tachometer located in 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 the grey wire. The ECU utilizes this information to regulate boost and fuel. It also sends an indication to the G5 Tachometer in instrument cluster.
The sensor is used as a reference to correlate with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft is TDC and where the camshaft is located so that it can trigger spark and injectors in the right way.
If this sensor fails, the ECU will display a P00160 error code. This indicates that the Crank Shaft is not in sync with the Intake Camshaft. It could also be a sign of an issue with the chain or a jump in the chain link of the upper timing chain. The code will not appear without the additional information supplied by other sensors (G4 or G40).
Testing can be a bit difficult as there are two different connector pins, and they have different functions but the most effective method to test it is to measure resistance between the sensor and the ECU. It should read about 1000 ohms if the sensor is at full operation. If you're experiencing issues with this part, check for signs of coolant or oil in the connector bay.
2. Injectors
Yesterday, while accelerating at full speed from the highway paytoll, I experienced a big cut in power as if the engine was running out of gas or the injectors aren't firing anymore. I pulled out the spark plugs this morning, three were soaked with gasoline and the fourth was unclean. I put tissue over each injector hole, and when i start the engine with no sparks, the three that have gazoline pop right out. The 4th one remains shut. I tested the ground connection of ECU pins 14,30 and 48/55. I got zero ohm. I think the issue is somewhere else.
I also tried to reset the PID with no success. The car will start when the G28 is disconnected, but it works fine when the G28 plugged in. However, the intermittent misfire problem continues to occur at higher RPM. The temperature sensor for coolant (G62) shows the wrong temp value that is -49c even after unplugging it. I also noticed that the oil gauge in the cockpit shows 2 bar while the actual pressure is 0.
I'm not sure what to do, i feel i have pretty much eliminated everything else. However, i'm afraid that I might have missed something. Let me know should you have any suggestions! TIA!
3. Fuel Pump
The fuel pump in the g28 can replacement key for audi a4 be activated by a signal by 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. It is easy to find an extra in a wrecking shop or a parts store. Test them out - put your DMM in resistance mode and measure between pins 1 (with the bump on the connector end up) and 2 (2nd from left on the black end of the connector). They should be infinite Ohms.
4. ECU
The ECU of our 20vt turbo (3B AAN ABY) engines must be aware of the position and speed the crankshaft to make decisions regarding timing of fuel injectors, etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If you are experiencing issues with either one of these, the here diagnostic scanner will show codes that could cause an engine shutdown.
A damaged G28 sensor can website cause an inaccurate speed counter for the gearbox and a gearbox which shifts more quickly than normal, or a misfire while in gear. It is possible that the sensor is failing and requires to be replaced if you notice any of these signs. They're cheap and easy to find particularly when they're an Bosch unit like check here ours. If you prefer, GM's version of this part is a good option.
5. Tachometer
A failing engine sensor could cause a number of problems in your car. It's an essential component of the transmission in your Audi, as it transmits information to the ECU regarding how fast or slowly the car's engine is turning. When this sensor fails, it could affect the performance of the transmission, as well as the other car's components.
The G5 engine speed sensor is located at the edge of the transmission just above the flywheel ring gear and sends a signal to the ECU at pin T55/49, via a grey wire. The ECU audi car key replacement utilizes this signal to regulate fuel and boost, as well as timig. It also sends it to the G5 Tachometer in 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 to pin T6a/1 (trace [79trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. You should see an average resistance of 1000 ohms in these areas. This is a common 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.