Your Worst Nightmare About Audi G28 Be Realized
Your Worst Nightmare About Audi G28 Be Realized
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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 transmission's edge just above the flywheel gear. It transmits a signal to the ECU through the grey wire T55/49 and then to the tachometer located on 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 a signal to ECU pin T55/49 using a grey wire. The ECU utilizes this information to regulate fuel and boost. It also sends an indication to the G5 tachometer in the instrument cluster.
The sensor is used as a reference for comparing with the G40 Camshaft Position Sensor. The ecu has to know when the crankshaft 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 message. This indicates that the Crank Shaft is not in sync with the Intake Camshaft. It could also indicate an issue with the chain or a jumpy chain link in the upper timing chain. However the code will not appear on its own, without additional information from other sensors (G4 and G40).
Testing can be a bit difficult as there are two different pins for the connector and they have different functions but the best way to test it is to measure the resistance between the sensor and the ECU. When the sensor is operational, it should read approximately 1000 ohms. If you're experiencing issues with this sensor, look for evidence of coolant or oil in the connector bay.
2. Injectors
Yesterday, when i was accelerating to the fullest speed from highway paytoll, i experienced massive power loss like the engine is running out of gas or the injectors are not firing at all. I pulled out the spark plugs this morning, three were drenched in gasoline and the fourth was dry. When I crank the engine, there are no sparks, I put a piece of tissue on the top of each hole in the injector, the 3 drenched with gazoline pop out, but the 4th stay closed. I inspected the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I got 0ohm. I'm assuming the issue is elsewhere.
I also tried to reset the PID without more info success. The car will start when the G28 is not plugged in and runs fine when it is connected but it still has the intermittent misfire issue at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature value of -49c even when i unplug it. Also, i noticed that the gauge for oil pressure in the cockpit is showing 2 bar, whereas the actual pressure is 0.0 if read more i crank up the engine.
I'm not certain what to do, i feel i have pretty much eliminated everything else. 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 from the RPM sensor. The GM-style sender is identical to the G4 and they both work in the 80 100, 200, UrS and RS2 cars which is why you can easily locate one at a wrecking yard or in a local parts store. It is simple to test them - put your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector's side up) and 2 (2nd from the left on the black end of the connector). They must be infinite Ohms.
4. ECU
The ECU of our 20vt turbo (3B AAN ABY ADU) engines needs to know both the speed and position of the crankshaft to determine fuel injector timing, etc. To accomplish this, it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you encounter a problem with either of these sensors, the diagnostic scanner will display codes that could lead to an engine shutdown.
A malfunctioning G28 sensor can cause an inaccurate speed counter for the gearbox or a gearbox that shifts faster than normal, and/or a misfire in the gear. It is possible that your sensor is failing and requires to be replaced if you notice any of these signs. The good thing is that they are quite affordable and easy to find particularly if you're looking at a Bosch sensor, which is what ours are. Alternatively, GM's version of this component is an excellent choice.
5. Tachometer
A malfunctioning engine sensor can cause a myriad of issues 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 rotating. If this sensor fails, it could cause problems for the transmission and the rest of more info the car's components.
The G5 engine sensor is located at the edge of the transmission, just above the flywheel ring. It transmits read more an electrical signal through gray wire to ECU pin T55/49. The ECU utilizes this signal to regulate the flow of fuel and boost and also timig. It also relays it to the G5 Tachometer in instrument cluster. You can check the sensor for any failure by checking the continuity between it and the tachometer. You can also check continuity between ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. You should observe approximately 1000 check here ohms of resistance between these two points. This is a standard component across the Audi 80 100, 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU so good ones could be available in wrecking yards.