The 3 Largest Disasters In Audi G28 History
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 edge of the transmission above the flywheel ring gear. It transmits a signal to the ECU via an uncolored wire (T55/49), then to the tachometer in the instrument cluster.
1. Engine Speed Sensor
The sensor is located at the edge of the transmission just above the flywheel ring gear G28 Engine Speed Sensor sends signals to ECU pin T55/49 via an uncolored wire. The ECU uses this information to control the amount of fuel and boost. It also sends an indication to the G5 tachometer inside 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 the location of the camshaft to trigger the spark and injectors.
If this sensor fails to function, the ECU will display a P00160 error code. This means that the Crank Shaft is out of sync with the Intake Camshaft. It could also be a sign of the possibility of a chain stretch or jump in the chain link of the upper chain. The code won't show without the additional information supplied by other sensors (G4 or G40).
Testing is a bit challenging as there are two different connector pins and they perform different functions but the most effective method to test it is to measure resistance between the sensor and the ECU. It should read approximately 1000 ohms if the sensor is operating at its maximum. Look for signs of coolant or oil in the connector bay if there are issues with this component.
2. Injectors
Yesterday, while accelerating from the highway paytoll at a high speed I noticed a massive drop in power. It was as if the engine had run out of gas. Or, my injectors were not firing. I pulled out the spark plugs this morning and found that 3 were soaked in gasoline, and the fourth was unclean. I put tissue over each injector hole and when I start the engine without sparks, the 3 with gazoline jump out. The fourth one remains 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 disconnected, but it runs fine with the G28 connected. However, the intermittent misfire problem continues to occur at higher RPM. The coolant temperature sensor (G62) shows the wrong temperature of that is -49c even after unplugging it. Also i noticed that the oil pressure gauge in the cockpit is showing 2 bar while the actual pressure is 0.0 when I crank up the engine.
I don't know what to do. I think I've all other possibilities out. However, i'm afraid that I may have missed something. Please let me know If you have any suggestions! TIA!
3. Fuel Pump
The fuel pump on the g28 is activated by a signal by the RPM sensor. The GM-style transmitter is identical to the G4 sender and works on the 80,100,200, UrS, and RS2 vehicles. You can easily locate a spare in a wrecking shop or parts store. Testing them is easy by putting 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 connector's side). They must be infinite Ohms.
4. ECU
The ECU of our 20vt turbo (3B AAN ABY ADU) engines must know the position and speed of the crankshaft to determine timing of fuel injectors, etc. To do this, it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you are experiencing issues with either one of these, the diagnostic scanner will display the codes that could trigger the engine shutting down.
A failing G28 sensor could result in an inaccurate speed counter for your gearbox, a gearbox that shifts faster than normal, or a misfire while in the gear. If how to get a new audi key experience any of these issues, it is most likely that your sensor is failing and should be replaced. They're inexpensive and easy to locate, especially in the case of an Bosch model like ours. If you prefer, GM's version of this part would be an excellent choice.
5. Tachometer
A failing engine sensor could cause a number of problems in your vehicle. It's a crucial component of the transmission in your Audi because it relays information to the ECU on how fast or slow the engine is turning. This sensor could cause the transmission to malfunction and other components of the car to be affected.
The G5 engine speed sensor is situated on the edge of the transmission just above the flywheel ring gear and transmits a signal to the ECU at pin T55/49 via an uncolored wire. The ECU then uses and processes the signal to control fuel, timig and boost as well as sends it on to the G5 tachometer in the instrument cluster. You can check the sensor for failure by examining the continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. You should see a resistance of approximately 1000 ohms between these points. This is a common feature across the Audi 80-100-200-RS2 range, from the 1985 MC all the way up to the 1997 UrS AN and 1995 RS2 Du So, you may find them in wrecking yards.