The Biggest "Myths" About Audi G28 Could Be True
The Biggest "Myths" About Audi G28 Could Be True
Blog Article
How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. The sensor is located at the top of the transmission just above the flywheel ring gear. It transmits a signal to the ECU via the grey wire (T55/49) and then to the tachometer located in the instrument cluster.
1. Engine Speed Sensor
The grey wire is located on the edge of transmission, above the flywheel ring. This sensor sends a signal via the grey wire to pin T55/49. The ECU uses this information to regulate boost and fuel. It also sends an alert to the G5 Tachometer located in the instrument cluster.
The sensor is used as a reference to correlate with 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 in the right way.
If this sensor fails, the ECU will display a P00160 error message. This means that the Crank Shaft is out of sync with the Intake Camshaft. It could also indicate the possibility of a chain stretch or jumpy chain link in the upper chain of timing. The code won't show without the additional information supplied by other sensors (G4 or G40).
Testing is a bit challenging since there are two connector pins and they perform different functions however the best method to test it is by measuring resistance between the sensor and the ECU. It should read about 1000 ohms when it is in full operation. If you're experiencing issues with this part, check for evidence of coolant or oil in the connector bay.
2. Injectors
Yesterday, when accelerating from 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 weren't firing. I took out the spark plugs this morning and found that 3 were soaked in gasoline, and the fourth was unclean. When I start the engine with no sparks i put tissue on the top of each hole in the injector and the 3 drenched with gazoline leap out, however the 4th stays shut. I tested the ground connection of ECU pins 14,30, and 48/55. I got zero ohm. So i assume the problem is in another place.
I also tried to reset the PID but without success. The car will get more info start when the G28 is not plugged in and it runs perfectly when it is plugged in, but still has the intermittent misfire issue at higher RPM. The coolant sensor (G62) even when unplugged, still shows get more info an ice temperature of -49c. Also, i noticed that the gauge for oil pressure in the cockpit is showing 2 bar when the actual pressure is 0.0 when I crank up the engine.
I'm not sure what to do. I feel like i've pretty much all other possibilities out. But i'm worried that I might read more have missed something. If anyone has suggestions, please share them! TIA!
3. Fuel Pump
The fuel pump in the g28 receives signals from 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 wrecking yard or at a parts store. It is easy to test them: simply put your DMM into resistance mode and determine 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 are equipped with an ECU that has to be aware of the speed and position more info of the crankshaft to make a decision about fuel injector timing etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you have a problem with either of these, the diagnostic scanner will display the codes that could trigger an engine shut down.
Some of the symptoms of a failing G28 sensor are an inaccurate rev counter for the gearbox and gears that shift faster than normal and/or misfiring when in gear. If you are experiencing any of these issues, it is likely your sensor is going bad and needs replacing. The good news is they are very cheap and easy to find, especially if you're looking at the Bosch model, like ours. Alternately, the GM version of this component is also a great option.
5. Tachometer
A faulty engine speed sensor could be the reason behind numerous issues in your vehicle. It is an important part of the transmission of your Audi since it sends information to the ECU about how fast or slowly the engine is spinning. This sensor could cause the transmission to malfunction and other components in the car to be affected.
The G5 engine sensor is located near the edge of the transmission, just above the flywheel ring. It sends signals via an uncolored wire to the ECU pin T55/49. The ECU utilizes this signal to control the flow of fuel and boost and also to timigrate. It also sends it to the G5 Tachometer located in the instrument cluster. You spare audi key can test for sensor failure by checking continuity from the sensor to the tachometer. Additionally, you can 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 an average resistance of 1000 ohms in these areas. This part is common across the Audi 80-100-200-RS2 series, starting beginning with the 1985 MC and up to the 1997 UrS AN and the 1995 RS2 DU You may also find them in wrecking yards.