5 Laws Everybody In Audi G28 Should Be Aware Of
How to Replace an audi car key holder q7 replacement audi a3 key (More Support) G28 Engine Speed Sensor
In this video, Charles the Humble Mechanic demonstrates how to replace the G28 engine speed sensor. The sensor is situated on the edge of the transmission just above the flywheel ring gear. It sends a message to the ECU via the grey wire T55/49 and then to the tachometer in the instrument cluster.
1. Engine Speed Sensor
The grey wire is located at the edges of the transmission, just above the flywheel ring. The sensor transmits signals through the grey wire to pin T55/49. The ECU utilizes this information to control fuel and boost. It also sends an indication to the G5 Tachometer located in the instrument cluster.
The sensor serves as a reference for comparing with the G40 Camshaft Position Sensor. The ecu must be aware of when the crankshaft has reached TDC, and the position of the camshaft, to trigger the spark and injectors.
If this sensor fails the ECU will show an error code P00160 which indicates that the Crank Shaft and Intake Camshaft aren't in sync and could indicate the chain is stretched or a jump link on the upper timing chain. However, the code won't appear on its own, without additional information from other sensors (G4 and G40).
Testing can be a bit difficult because there are two connector pins and they serve different purposes but the most effective method of testing it is to measure the resistance between the sensor and the ECU. It should read about 1000 ohms when it is at full operation. If you're having issues with this sensor, look for signs of oil or coolant in the connector bay.
2. Injectors
Yesterday, as i was accelerating off the highway paytoll at a high speed I noticed a massive decrease in power. It was like the engine was running out of gas. Or my injectors were not firing. This morning i pull out the spark plugs, three were soaked with gazoline and the fourth one was dry. When I crank the engine with no sparks, i place a tissue on top of each injector hole and the 3 drenched with gazoline leap out, however the 4th stay shut. I tested the ground connection of ECU pins 14,30, and 48/55. I found 0ohm. I assume that the problem is somewhere else.
I also tried to reset the PID but without success. The car is able to start if the G28 is unplugged and runs fine when it is connected, but still is experiencing intermittent misfires at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature of -49c, even if I unplug it. I also noticed that the oil gauge in the cockpit shows 2 bars but the actual pressure is zero.
I don't know what to do. I believe that I've eliminated everything else. I'm afraid i may have missed something. If anyone has any suggestions, please chime in! TIA!
3. Fuel Pump
The fuel pump on the g28 is activated by a signal from the RPM sensor. The GM-style transmitter is similar to the G4 sender and works on the 80,100,200, UrS, and RS2 vehicles. You can easily locate an extra in a wrecking shop or a parts store. It is easy to test them - simply put your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump at the connector end facing upwards). They must be infinite Ohms.
4. ECU
The ECU of our 20vt turbo (3B AAN ABY) engines requires to be aware of the speed and position of the crankshaft in order to make a decision about timing of the fuel injector, etc. To do this, it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these goes bad you will get codes on the diagnostic scanner which can lead to engine shutdown.
Some of the symptoms of a failed G28 sensor include an inaccurate gearbox rev counter, gears shifting quicker than normal and/or a misfire when you're in gear. It is likely that the sensor is failing and needs to be replaced if you notice any of these signs. They're inexpensive and easy to locate especially in the case of an Bosch model like ours. Alternatively, the GM version of this part is also a good choice.
5. Tachometer
A malfunctioning engine speed sensor could be the cause of many issues in your car. It's an essential component of your audi advanced key's transmission, as it sends information to the ECU about how the car's crankshaft is turning. This sensor could cause the transmission to malfunction and other components in the car to be affected.
The G5 engine speed sensor is situated on the edge 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 then uses and processes the signal to control the flow of fuel, timig and boost and then sends it on to the G5 tachometer in the instrument cluster. You can check the sensor for failure by examining the 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]) and between pin T6a/1 and the instrument cluster pin T26a/12. You should see approximately 1000 ohms resistance between those two pins. This is a standard part that is found across the audi a1 key 80, 100, 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU, so the best ones could be available in wrecking yards.