How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician shows you how to replace the G28 Engine Speed Sensor. This sensor is situated on the outside of the transmission, above 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 grey wire is located at the edges of the transmission, above the flywheel ring. This sensor sends a signal via the grey wire to pin T55/49. The ECU then uses this information to control 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 must know when the crankshaft is TDC and where the camshaft is located so that it can activate spark and injectors accordingly.
If this sensor fails to function, the ECU will display a P00160 error code. This indicates that the Crank Shaft is out of line with the Intake Camshaft. It could also indicate a chain stretch or a jumpy chain link in the upper timing chain. The code won't show without the additional information provided by other sensors (G4 or G40).
It is a little tricky to test because there are various pins on the connector and each one has different functions. The most effective method to test it is by measuring the resistance between the ECU and the sensor. If the sensor is operational, it should be reading about 1000 ohms. If you are having problems with this part, check for signs of coolant or oil in the connector bay.
2. Injectors
Yesterday, when i was accelerating to the fullest speed from highway paytoll, i experienced massive power loss like the engine is out of gas or the injectors are not firing anymore. This morning i pull out the spark plugs, 3 were drenched with gazoline the fourth was dry. I put tissue over each injector hole, and when I start the engine with no sparks, the three with gazoline jump right out. The fourth one remains closed. I inspected the ground connection on ECU pins 14/55,30/55 and 48/55 i get 0ohm. Therefore, i think the issue is elsewhere.
I also tried to reset the PID but with no luck. The car will start when the G28 is disconnected, but it is running fine with the G28 plugged in. However, the intermittent misfire problem continues to occur at higher RPM. The coolant sensor (G62), even when it is unplugged, shows temperatures of -49c. I also noticed that the oil gauge in the cockpit shows 2 bar when the actual pressure is zero.
I'm not sure what to do, but i think i've pretty much ruled out everything else. I'm concerned that i may have missed something. Let me know if you have any ideas! 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 a spare in a wrecking shop or parts store. It is easy to test them - just put your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump at the connector's end facing upwards). They should be infinite Ohms.
4. ECU
Our 20vt turbo (3B, AAN, ABY and ADU) engines have an ECU that needs to be aware of the speed and position of the crankshaft in order to make decisions regarding timing of the fuel injector, for example. To do this, it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these go bad you will get codes on the diagnostic scanner that could cause engine shut down.
A damaged G28 sensor can cause an inaccurate speed counter for your gearbox and a gearbox which shifts more quickly than normal, and/or a misfire in gear. If you have any of these check here issues, it is likely your sensor is deteriorating and needs replacing. The good news is they are quite affordable and readily available, especially in the case of a Bosch model, like ours. If you prefer, GM's version of this part would be a good option.
5. Tachometer
A malfunctioning engine speed sensor could be click here the cause of many issues with your vehicle. It's an essential component of your Audi's transmission, as it sends information to the ECU about how fast or slow the vehicle's crankshaft is turning. When this sensor fails, it will cause problems for the transmission, as well as the other car's components.
The G5 website 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 through a grey wire. The ECU then processes this click here signal to regulate the flow of fuel, timig and boost as well as transmitting it to the G5 Tachometer located in the instrument cluster. You can test the sensor for failure by examining the continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection on pin T6a/1 (trace [79trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. It should show around 1000 ohms of resistance between those points. This is a common feature across the Audi 80-100-200-RS2 range, beginning with the 1985 MC and up to the 1997 UrS AN and 1995 more info RS2 Du, so you might find some good ones in wrecking yards.