"The Ultimate Cheat Sheet On Audi G28
"The Ultimate Cheat Sheet On Audi G28
Blog Article
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 over the flywheel gear. It sends a signal to the ECU via a grey wire (T55/49) and then to the tachometer located in 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 via a grey wire. The ECU then uses this information to control 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 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 trigger spark and injectors accordingly.
If this sensor fails the ECU will show the P00160 error, which means the Crank Shaft and Intake Camshaft are not in sync and possibly indicating the chain is stretched or a jump link on the upper chain of timing. However the code will not be displayed on its own without additional information from other sensors (G4 and G40).
It can be a bit difficult to test since there are various connector pins, and they all have different functions. The best method for doing this is by measuring the resistance between the ECU and the sensor. It should read about 1000 ohms when the sensor is in full operation. Look for signs of coolant, or oil in the connector bay if you have problems with this part.
2. Injectors
Yesterday, while accelerating at full speed from the highway paytoll, I experienced a big cut in power as if the engine was running out of gas or the injectors are not firing anymore. I took out the spark plugs this morning and found that 3 were soaked in gasoline, and the fourth 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 4th one stays closed. I checked the ground connection on ECU pins 14/55,30/55 and 48/55 i get 0ohm. I assume that the problem is somewhere else.
I also tried to reset the PID with no success. The car will start when the G28 is unplugged, and it runs fine with the G28 plugged in. However, the intermittent misfire problem continues to audi a1 key occur at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature value of -49c, even if I unplug it. I also noticed that the oil gauge in the cockpit shows 2 bar when the actual pressure is zero.
I'm not certain what to do, but i feel i have pretty much completely ruled out all other possibilities. I'm afraid i may have missed something. Please let me know should you have any suggestions! TIA!
3. Fuel Pump
The fuel pump on the g28 is activated by a signal by the RPM sensor. The GM-style transmitter is similar to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. It is easy to find a spare in a wrecking shop or a parts store. Testing them is easy to do - just put your DMM in resistance mode and measure between pins 1 (with the bump on the connector's end up) and 2 (2nd from the left on the black connector's end). They must be infinite Ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY) engines must know the position and speed the crankshaft in order to make a decision about timing of fuel injectors, etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these sensors go wrong, you will receive codes on the diagnostic scanner that can check here lead to engine shutdown.
Some of the signs of a malfunctioning G28 sensor are an inaccurate rev counter in the gearbox and gears that shift faster than normal, and/or a misfire when in gear. It is possible that your sensor is failing and needs to be replaced if you notice any of these symptoms. They're cheap and easy to find especially in the case of an Bosch sensor like ours. Alternatively, GM's version of this part would be an excellent choice.
5. Tachometer
A failing engine sensor could cause a number of problems read more within your vehicle. It is an important part of the transmission of your Audi since it sends information to the ECU about how fast or slow the engine is turning. This sensor can cause the transmission to fail and other components of the car to be affected.
The G5 engine speed sensor is situated get more info on the edge of the transmission just above the flywheel ring gear and sends a signal directly to the ECU at pin T55/49, via an uncolored wire. The ECU is then able to process this signal to control fuel, timig, and boost, and also transmitting it to the G5 Tachometer located in the instrument website cluster. You can determine if the sensor is in failure by examining the continuity of 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 [79trace [79]) and between pin T6a/1 as well as pin T26a/12. There should be a resistance of approximately 1000 ohms in these areas. This part is common across the Audi 80-100-200-RS2 series, starting from the 1985 MC all the way up to the 1997 UrS AN and 1995 RS2 Du You may also find good ones in wrecking yards.