Why No One Cares About Audi G28
Why No One Cares About Audi G28
Blog Article
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 situated at the edge of transmission just above the flywheel gear. It sends a message to the ECU through an uncolored wire T55/49, then to the tachometer on the instrument cluster.
1. Engine Speed Sensor
It is located on the outside of the transmission, above the flywheel ring gear, the G28 Engine Speed Sensor sends an electrical signal to ECU pin T55/49 through an uncolored wire. The ECU then utilizes this information to regulate the flow of fuel, timig and boost. It also sends an indication to the G5 Tachometer within the instrument cluster.
The sensor serves as a reference point to connect with the G40 Camshaft Position Sensor. The ecu has to know when the crankshaft reached TDC, and the location of the camshaft in order to activate the spark and injectors.
If this sensor fails, the ECU will display a P00160 code which means the Crank Shaft and Intake Camshaft are out of sync and could indicate the chain stretching or a jump link on the upper timing chain. The code won't appear without the additional information provided by other sensors (G4 or G40).
It's a bit tricky to test as there are various pins on the connector, and each has its own functions. The best way to do it is to measure the resistance between the ECU and the sensor. It should read approximately 1000 ohms when it is at full operation. Check for evidence of coolant or oil in the connector bay if there are issues with this part.
2. Injectors
Yesterday, as i was accelerating off the highway paytoll at maximum speed I noticed a significant drop in power. It was like 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 with gasoline and the 4th was dry. I put a piece of tissue over each injector hole, and when i turn the engine on without sparks, the 3 with gazoline jump right out. The fourth one remains closed. I tested the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I got zero Ohm. So i assume the problem is somewhere else.
I also tried to reset PID without success. The car will start when the G28 is unplugged, and it is running fine with the G28 connected. However, the intermittent misfire problem audi a4 car key replacement continues to occur at higher RPM. The coolant sensor (G62), even when it is unplugged, shows temperatures of -49c. Also i noticed that the gauge for oil pressure in the cockpit shows 2 bar, whereas the actual pressure is 0.0 if i crank up the engine.
I'm not sure what to do, i believe that i've eliminated everything else. But i'm worried that I might have missed something. Please let me know if you have any ideas! TIA!
3. Fuel Pump
The fuel pump in the g28 can be activated by a signal by the RPM sensor. The GM-style sender is identical to the G4 and both function in here the 80 100 200, UrS and RS2 cars so you can easily find one at a wrecking yard or in a local parts store. It is easy to test them - simply put your DMM into resistance mode and test the distance between pins 1 and 2 (with the bump at the connector end facing upwards). They must 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 regarding fuel injector timing etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If either of these sensors go badly, you will see codes on the diagnostic scanner which can lead to engine shutdown.
Some of the symptoms of a malfunctioning G28 sensor include an inaccurate gearbox rev counter, gears shifting quicker than normal and/or a misfire when you're in gear. If you experience any of these issues it is most likely that your sensor is failing and should be replaced. The good thing is that they are very affordable and easily accessible, especially if you're looking at a Bosch unit which is what we have. You can also choose the GM version of this part is also a good option.
5. Tachometer
A failing engine sensor could cause a variety of issues in your vehicle. It's a vital component of your Audi's transmission, because it communicates to the ECU about how fast or slow the vehicle's crankshaft is rotating. This sensor could cause the transmission more info to fail and other components in the car to be affected.
The G5 engine sensor is located at the edge of transmission, above the flywheel ring. It sends an electrical signal through gray wire to ECU pin T55/49. The ECU utilizes this signal to control fuel and boost, and also timig. It also transmits it to the G5 Tachometer located in the instrument cluster. You can check for sensor failure by examining the continuity from the sensor to the tachometer. Additionally, you can verify continuity between pin T55/49 of get more info the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]), and between pin T6a/1 and pin T26a/12. You should detect a resistance of approximately 1000 ohms between these points. This is click here a standard component across the Audi 80, 100 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU so good ones could be available in wrecking yards.