The Ugly Reality About Audi G28
The Ugly Reality About 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 at the edge of transmission over the flywheel gear. It transmits a signal the ECU via a grey wire (T55/49) which is then sent to the tachometer in the instrument cluster.
1. Engine Speed Sensor
The grey wire is located at the edges of the transmission, above the flywheel ring. The sensor sends a signal via the grey wire to pin T55/49. The ECU then uses this information to control the flow of 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 know when the crankshaft reached TDC and also where the camshaft lies to trigger the spark and injectors.
If this sensor fails, the ECU will display an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are out of sync, possibly indicating the chain is stretched or a jump link on the upper chain of timing. The code will not appear without the additional information provided by other sensors (G4 or G40).
It can be a bit difficult to test as there are several pins on the connector and each one has different functions. The most effective method to test it is to measure the resistance between the ECU and the sensor. When the sensor is fully operational, it should be reading around 1000 ohms. If you're having issues with this part, check for signs of coolant or oil in the connector bay.
2. Injectors
Yesterday, while accelerating at full speed from the highway paytoll, i experienced an abrupt drop in power as if the engine was running out of gas or the injectors aren't firing any more. I pulled out the spark plugs this morning, 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 ones with gazoline jump right out. The 4th one stays closed. I inspected the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ i get zero ohm. I assume that the problem is in another location.
I also tried to reset the PID audi a5 replacement key without success. The car will start when the G28 is disconnected, but it works fine when the G28 plugged in. However, the intermittent misfire problem continues to occur at higher RPM. The coolant temperature sensor (G62) shows the wrong temperature value of -49c even when i unplug it. I also noticed that the oil gauge in the cockpit shows 2 bars when the actual pressure is zero.
I'm not certain what to do, i believe that i've completely ruled out all other possibilities. But i'm worried that I might have missed something. If get more info anyone has any suggestions, please chime in! TIA!
3. Fuel Pump
The fuel pump in the g28 receives a signal from the RPM sensor. The GM-style sensor is the same as the G4 and they both work in the 80, 100, 200, UrS and RS2 cars which is why you can easily locate one at a salvage yard or in a local parts store. It is easy to test them - simply switch 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
Our 20vt turbo (3B AAN, ABY, and ADU) engines are here equipped with an ECU that must be aware of the speed and position of the crankshaft in order to make a decision about timing of the fuel injectors, 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, you will receive codes on the diagnostic scanner which could cause engine shut down.
Some of the audi spare key symptoms of a malfunctioning G28 sensor are an inaccurate rev counter for the gearbox the gears are shifting faster than normal and/or a misfire when you're in gear. It is probable that your sensor is failing and needs to be replaced if you encounter any of these symptoms. The good thing is that they are quite affordable and easily accessible, especially when you're looking at the Bosch unit which is what ours are. Alternately, GM's version this part would be a good option.
5. Tachometer
A failing engine sensor could cause a number of problems in your car. It is an important part of the transmission in your Audi since it sends information to the ECU on how fast or slowly the engine is spinning. This sensor could cause the transmission to malfunction and other components in the car to be affected.
The G5 engine sensor is located near the edge of the transmission, just above the flywheel ring. It transmits an electrical signal through an uncolored wire to the ECU pin T55/49. The ECU is then able to process the signal to control the flow of fuel, timig and boost as well as sends it on to here the G5 tachometer inside the instrument cluster. You can check the sensor for failure by checking continuity between it and the tachometer. You can also check continuity between ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. There should be the resistance to be around 1000 ohms between these two points. This is a common feature across the Audi 80-100-200-RS2 model, ranging from the 1985 MC up to the 1997 UrS An and 1995 RS2 Du You may also find good ones in wrecking yards.