This Is The Ugly Real Truth Of Audi G28
This Is The Ugly Real Truth Of Audi G28
Blog Article
How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician teaches you how to replace the G28 Engine Speed Sensor. This sensor is located on the outside of the transmission over the flywheel gear. It sends a signal to the ECU via an uncolored wire (T55/49) which is then sent to the tachometer located in the instrument cluster.
1. Engine Speed Sensor
The sensor is located at the edge of the transmission above the flywheel ring gear, the G28 Engine Speed Sensor sends a signal to ECU pin T55/49 using an uncolored wire. The ECU then utilizes this information to regulate fuel, timig and boost. It also sends an indication to the G5 Tachometer located in the instrument cluster.
The sensor is used as a reference for comparing with the G40 Camshaft Position Sensor. The ecu must be aware when the crankshaft is TDC and where the camshaft is located so that it can activate spark and injectors according to the situation.
If this sensor fails to function, the ECU will display a P00160 error message. This means that the Crank Shaft is out of alignment with the Intake Camshaft. It could also indicate the possibility of a chain stretch or jumped chain link in the upper timing chain. The code won't show without the additional information supplied by other sensors (G4 or G40).
It's a bit tricky to test because there are various pins on the connector and each has its own functions. The most effective method to test it is by measuring the resistance between the ECU and the sensor. It should read about 1000 ohms if the sensor is in full operation. If you're experiencing issues with this component, look for evidence of coolant or oil in the connector bay.
2. Injectors
Yesterday, while accelerating from the highway paytoll at maximum speed I noticed a massive drop in power. It was as if the engine was running out of gas. Or my injectors weren't firing. In the morning, i removed the spark plugs, 3 were drenched with gazoline the fourth was dry. I put a piece of tissue over each injector hole, and when i start the engine without sparks, the 3 that have gazoline pop right out. The fourth one remains shut. I tested the ground connection of ECU pins 14,30, and 48/55. I found 0ohm. I'm assuming the issue is somewhere else.
I also tried to reset the PID without success. The car is able to start when the G28 is disconnected and here it runs perfectly when it is connected however it is experiencing intermittent misfires at higher RPM. The coolant temperature sensor (G62) shows the wrong temp value -49c even when i unplug it. I also noticed that the oil gauge in the cockpit shows 2 bars while the actual pressure is zero.
I'm not certain what to do, as i feel i have pretty much completely ruled out all other possibilities. But i am afraid I might have missed something. If anyone has any suggestions, please share them! TIA!
3. Fuel Pump
The fuel pump in the g28 receives a signal from the RPM sensor. The GM-style transmitter functions similarly to the G4 sender and works on the 80,100,200, UrS, and RS2 vehicles. You can easily find website the spare in get more info a salvage shop or parts store. Test them out to do - just put your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector end up) and 2 (2nd from left on the black connector's side). They should be infinite Ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY) engines must be aware of the speed and position of the crankshaft in order to make a decision about timing of fuel injectors, etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you have a problem with either of audi keys these sensors, the diagnostic scanner will show the codes that could trigger an engine shut down.
Some of the symptoms of a failing G28 sensor include an inaccurate rev counter for the gearbox the gears are shifting faster than normal, and/or a misfire when you are in gear. If you are experiencing any of these here issues it is most likely that your sensor is failing and requires replacement. The good news is they are quite affordable and easy to find, especially in the case of the Bosch unit which is what ours are. If you prefer, GM's version of this component is an excellent choice.
5. Tachometer
A damaged engine sensor could cause a number of problems in your vehicle. It's an essential component of the transmission of your Audi, as it transmits information to the ECU regarding how fast or slow the car's engine is turning. This sensor can cause the transmission to fail and other components in the car to be affected.
The G5 engine speed sensor is located at the edge of the transmission, above the flywheel ring gear and sends a signal directly to the ECU at pin T55/49 via an uncolored wire. The ECU then processes this signal to regulate fuel, timig, and boost and then sends it on to the G5 tachometer in the instrument cluster. You can check for sensor failure by examining the continuity of the sensor to the tachometer. You can also examine the continuity between pins T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]), and between pin T6a/1 and pin T26a/12. You should detect a resistance of approximately 1000 ohms between these two points. This is a typical component across the Audi 80 100, 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU so good parts could be found in wrecking yards.