What's The Current Job Market For Audi G28 Professionals?
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. The sensor is situated on the edge of the transmission above the flywheel ring gear. It transmits a signal to the ECU via a grey wire (T55/49) and then to the tachometer within the instrument cluster.
1. Engine Speed Sensor
Located on the edge of the transmission just above the flywheel ring gear the G28 Engine Speed Sensor sends signals to ECU pin T55/49 through the grey wire. The ECU utilizes this information to control fuel and boost. It also sends an indicator to the G5 Tachometer within the instrument cluster.
The sensor is used to correlate the G40 Camshaft position Sensor. The ecu has to know when the crankshaft reached TDC and also the location of the camshaft in order to activate the spark and injectors.
If this sensor fails, the ECU will throw the P00160 error, which means the Crank Shaft and Intake Camshaft are out of sync and possibly indicating chain stretch or a jumped link on the upper timing chain. The code won't show without the additional information provided by other sensors (G4 or G40).
It can be a bit difficult to test as there are several pins on the connector and each one has different functions. The best way to do it is by measuring the resistance between the ECU and the sensor. When the sensor is fully functional, it should read approximately 1000 ohms. Examine for evidence of coolant or oil in the connector bay if you are experiencing issues with this part.
2. Injectors
Yesterday, while accelerating at full speed from the highway paytoll, I experienced massive power loss as if the engine was running out of gas or injectors aren't firing at all. I pulled out the spark plugs this morning and found that 3 were soaked with gasoline and the 4th was dry. I put tissue over each injector hole and when I turn the engine on without sparks, the ones with gazoline jump out. The 4th one stays closed. I tested the ground connection on ECU pins 14/55,30/55 and 48/55 i get zero ohm. I think the issue is in another location.
I also tried to reset PID but without success. The car can start if the G28 is disconnected and runs fine when it is plugged in, but 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. Also i noticed that the gauge for oil pressure in the cockpit shows 2 bar while the actual pressure is 0.0 if i crank up the engine.
I'm not sure what to do. I think I've eliminated everything else. But i am afraid i might have missed something. Let me know If you have any suggestions! TIA!
3. Fuel Pump
The fuel pump in the g28 receives a signal from the RPM sensor. The GM-style transmitter is identical to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. You can easily locate an extra in a wrecking shop or a parts store. It is simple to test them - just put your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump at the connector end facing up). They should be infinite Ohms.
4. ECU
Our 20vt turbo (3B, AAN, ABY and ADU) engines have an ECU that has to be aware of the speed and position of the crankshaft in order to make decisions about fuel injector timing etc. In order to do this it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If spare audi key cost have a problem with either one of these, the diagnostic scanner will display codes that could lead to the engine shutting down.
The signs of a malfunctioning G28 sensor are an inaccurate gearbox rev counter and gears that shift faster than normal and/or a misfire when in gear. It is possible that the sensor is failing and needs to be replaced if you experience any of these symptoms. The good news is that they are very affordable and easily accessible, especially in the case of an Bosch model, which is what ours are. Alternately, GM's version this part would be a good option.
5. Tachometer
A failing engine speed sensor could be the cause of a slew of problems in your vehicle. It's a vital component of the Audi's transmission as it sends information to the ECU about how the car's crankshaft is turning. This sensor can cause the transmission to malfunction and other components in the car 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 through an uncolored wire. The ECU uses this signal to control the amount of fuel and boost, and also timig. It also transmits it 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 [79trace [79]) and between pin T6a/1 as well as pin T26a/12. You should detect the resistance to be around 1000 ohms in these areas. This is the same across the Audi 80-100-200-RS2 model, ranging from the 1985 MC all the way up to the 1997 UrS AN and the 1995 RS2 DU So, you may find them in wrecking yards.