4 Dirty Little Secrets About Audi G28 And The Audi G28 Industry
4 Dirty Little Secrets About Audi G28 And The Audi G28 Industry
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 transmits a signal to the ECU via an uncolored wire T55/49, then to the tachometer on the instrument cluster.
1. Engine Speed Sensor
The grey wire is situated on the outside of the 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 indicator to the G5 Tachometer within the instrument cluster.
The sensor is used to connect the G40 Camshaft position Sensor. The ecu must know when the crankshaft is TDC and where the camshaft is located so that it can trigger spark and injectors accordingly.
If this sensor fails the ECU will throw a P00160 code which means the Crank Shaft and Intake Camshaft aren't in sync, possibly indicating the chain stretching or a jump link on the upper timing chain. However the code will not appear on its own, without additional information from other sensors (G4 and G40).
It is a little tricky to test as there are different pins on the connector, and each has its own functions. The best method for doing this is to measure the resistance between the ECU and the sensor. It should read about 1000 ohms when the sensor is in full operation. If you're experiencing issues with this sensor, look for evidence of coolant or oil in the connector bay.
2. Injectors
Yesterday accelerating full speed from highway paytoll i had massive power loss like the engine is out of gas or injectors are not firing anymore. I pulled out the spark plugs this morning, 3 were soaked with gasoline and the fourth was unclean. When I start the engine without sparks i put tissue on the top of each hole in the injector and the 3 drenched with gazoline jump out but the 4th stay closed. I checked the ground connection of ECU pins 14,30, and 48/55. I got zero ohm. I'm assuming the issue is in another place.
I also tried to reset the PID without success. The car will start when the G28 is disconnected, but it works fine when the G28 plugged in. However the intermittent misfire issue persists at higher RPM. The coolant sensor (G62), even when it is unplugged, shows an ice temperature of -49c. Also, i noticed that the gauge for oil pressure in the cockpit shows 2 bar, whereas the actual pressure is 0.0 when i rev here the engine.
I'm not certain what to do, as i think i've pretty much eliminated everything else. I'm worried that i might have missed something. Please let me know should you have any here suggestions! TIA!
3. Fuel Pump
The fuel pump in 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 wrecking yard or in a local parts store. click here 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's end facing up). They should be infinite Ohms.
4. ECU
The ECU of our 20vt turbo (3B AAN ABY) engines requires to know both the position and speed of the crankshaft to make decisions regarding timing of the fuel injector, etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If you are experiencing issues with either one of these, the diagnostic scanner will display the codes get more info that could trigger an engine shutdown.
A malfunctioning G28 sensor can cause an inaccurate speed counter for the gearbox and a gearbox which shifts faster than normal, and/or an unfire when in the gear. It is likely that your sensor is failing and requires to be replaced if you encounter any of these symptoms. They are cheap and easy-to-find, especially when they're a Bosch model like ours. If you click here prefer, GM's version of this component is an option.
5. Tachometer
A failing engine sensor could cause a number of problems in your vehicle. It's a vital component of your Audi's transmission, because it communicates to the ECU about how the car's crankshaft is spinning. If the sensor fails, it could affect the performance of the transmission as well as the rest of the car's components.
The G5 engine speed sensor is located at the outside of the transmission, above the flywheel ring gear and transmits a signal to the ECU at pin T55/49 via an uncolored wire. The ECU is then able to process this signal to regulate fuel, timig and boost as well as transmitting it to the G5 Tachometer located in the instrument cluster. You can check the sensor for failure by checking continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. There should be a resistance of approximately 1000 ohms in these areas. This is the same across the Audi 80-100-200-RS2 series, starting beginning with the 1985 MC and up to the 1997 UrS An and 1995 RS2 Du, so you might find some good ones in wrecking yards.