5 Laws Anyone Working In Audi G28 Should Be Aware Of
5 Laws Anyone Working In Audi G28 Should Be Aware Of
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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 on the outside of the transmission, above the flywheel gear. It transmits a signal to the ECU through the grey wire T55/49 and then to the tachometer on the instrument cluster.
1. Engine Speed Sensor
The grey wire is located on the edge of transmission, directly above the flywheel ring. The sensor sends signals through the grey wire to pin T55/49. The ECU then uses this information to control fuel, timig and boost. It also sends an indication to the G5 Tachometer within the instrument cluster.
The sensor is used to connect the G40 Camshaft position Sensor. The ecu needs to be aware of when the crankshaft has reached TDC, and where the camshaft lies to trigger the spark and injectors.
If this sensor fails to function, the ECU will display an error code P00160. This means that the Crank Shaft is not in line with the Intake Camshaft. It could also indicate the possibility of a chain stretch or jump in the chain link of the upper chain of timing. The code will not appear without the additional information provided by other sensors (G4 or G40).
It can be a bit difficult to test because there are several pins on the connector and each one has different functions. The best way to do it is to measure the resistance between the ECU and the sensor. When the sensor is fully operational, it should be reading around 1000 ohms. Examine for signs of coolant, or oil in the connector bay if you have issues with this component.
2. Injectors
Yesterday accelerating full speed from highway paytoll i had an abrupt drop in power like the engine is out of gas or injectors aren't firing any more. I pulled out the spark plugs this morning, 3 were soaked with gasoline and the fourth was dry. I placed a tissue over each injector hole and when I turn the engine on without sparks, the ones with gazoline jump out. The 4th one stays shut. I checked the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ i get zero Ohm. I'm assuming that the issue is somewhere else.
I also tried to reset the PID get more info but without success. The car will start when the G28 is unplugged, and it runs fine with the G28 connected. However the intermittent misfire issue continues to occur at higher RPM. The coolant sensor (G62) website even when it is unplugged, shows 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 rev the engine.
I don't know what to do. I feel like i've pretty much ruled everything else out. However, i'm afraid that I might have missed something. If anyone has any ideas please chime in! TIA!
3. Fuel Pump
The fuel pump of the g28 receives signals from the RPM sensor. The GM-style transmitter is the same as the G4 and both are used in the 80, 100, 200, UrS and RS2 cars so you can easily find one at a salvage yard or from a parts store. It is simple to test them - just put your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump at the connector's end facing up). They should be infinite Ohms.
4. ECU
Our 20vt turbo (3B AAN, ABY, and ADU) engines have an ECU that needs to know the speed and position of the crankshaft in order to make decisions about fuel injector timing etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you encounter a problem with either of these sensors, the diagnostic scanner will display the codes that could trigger the engine shutting down.
Some of the symptoms of a failed G28 sensor include an inaccurate rev counter for the gearbox, gears shifting quicker than normal and/or misfiring when in gear. If you have any of these issues, it is likely your sensor is failing and needs replacing. The good news is they are quite affordable and readily available, especially when you're looking at the Bosch unit which is what we have. Alternatively, the GM version of this component is also a good option.
5. Tachometer
A faulty engine speed sensor could be the cause of a slew of problems in your car. It is an important part of the transmission in your Audi because it relays information to the ECU about how fast or slowly the engine of the car is turning. If the sensor fails, it will cause problems for the transmission, as well as the other car's components.
The G5 engine sensor is located at the edge of website transmission, above the flywheel ring. It sends a signal via a gray wire to the ECU pin T55/49. The ECU click here utilizes this signal to control fuel and boost, as well as timig. It also sends it to the G5 Tachometer located in the instrument cluster. You can determine if the sensor is in failure by examining the continuity of the sensor to the tachometer. Also, you can check continuity between pin T55/49 of check here the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]), and between pin T6a/1 and pin T26a/12. You should see the resistance to be around 1000 ohms between these two points. This is a common feature across the Audi 80-100-200-RS2 range, beginning with the 1985 MC and up to the 1997 UrS An and 1995 RS2 DU You may also find good ones in wrecking yards.