Audi G28: The Good, The Bad, And The Ugly
Audi G28: The Good, The Bad, And The Ugly
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 on the outside of the transmission just above the flywheel gear. It sends a message to the ECU through the grey wire T55/49 and then to the tachometer in 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 a grey 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 is used to correlate with the G40 Camshaft position Sensor. The ecu has to know when the crankshaft reached TDC, and where the camshaft lies 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 aren't in sync, possibly indicating chain stretch or a jumped link on the upper chain of timing. The code will not appear without the additional information supplied by other sensors (G4 or G40).
It is a little tricky to test because there are several 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. When the sensor is fully operational, it should read approximately 1000 ohms. Examine for evidence of coolant or oil in the connector bay if you are experiencing issues with this part.
2. Injectors
Yesterday, when i was accelerating to the fullest speed from highway paytoll i had an abrupt drop in power like the engine is running out of gas or injectors aren't firing any more. I pulled out the spark plugs this morning, three were soaked with gasoline and the fourth was unclean. 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 disconnected, but it runs fine with the G28 connected. However, the intermittent misfire problem persists at higher RPM. The temperature sensor for coolant (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 sure what to do, but i feel i have pretty much completely ruled out all other possibilities. But i'm worried that I might have missed something. check here If anyone has suggestions, please chime in! TIA!
3. Fuel Pump
The fuel pump in the g28 is activated by a signal by the RPM sensor. The GM-style transmitter is similar to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. It is easy to find a spare in a website wrecking shop or a parts store. It is simple 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's end facing upwards). They must be infinite Ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY ADU) read more engines needs to be aware of the position and speed of the crankshaft to make decisions regarding timing of the fuel injector, etc. In order to do this it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these sensors go wrong, audi a1 key you will receive codes on the diagnostic scanner that can lead to engine shutdown.
Some of the signs of a failing G28 sensor include an inaccurate rev counter in the gearbox and gears that shift faster than normal and/or a misfire when in gear. If you experience any of these problems, it is most likely audi car key that your sensor is deteriorating and should be replaced. They are cheap and easy-to-find especially in the case of an Bosch sensor like ours. Alternately, the GM version of this component is also a good choice.
5. Tachometer
A malfunctioning engine speed sensor could be the reason behind a slew of issues in your car. It's a crucial component of the transmission of your Audi because it relays information to the ECU on how fast or slow the engine of the car is spinning. If the sensor fails, it could disrupt the performance of the transmission, as well as the other car's components.
The G5 engine sensor is located at the outskirts of transmission, above the flywheel ring. It transmits a signal via a gray wire to the ECU pin T55/49. The ECU then processes this signal to regulate fuel, timig, and boost, and also sends it on to the G5 Tachometer located in the instrument cluster. You can test for sensor failure by checking continuity from the sensor to the tachometer. You can also check 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 approximately 1000 ohms of resistance between those points. This is 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. Good ones might be availble in wrecking yards.