"Ask Me Anything": Ten Responses To Your Questions About Audi G28
How to Replace an audi car key holder G28 Engine Speed Sensor
Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. This sensor is situated near the transmission's edge over the flywheel gear. It transmits a signal to the ECU via an uncolored wire (T55/49) and then to the tachometer in 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 a signal via the grey wire to pin T55/49. The ECU then utilizes this information to regulate the flow of fuel, timig and boost. It also sends an indication to the G5 tachometer inside the instrument cluster.
The sensor is used to link with the G40 Camshaft position Sensor. The ecu needs to 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 when it fails, the ECU will display an error code P00160. This indicates that the Crank Shaft is out of sync with the Intake Camshaft. It could also indicate a chain stretch or a jumpy chain link in the upper timing chain. However, the error code won't appear on its own without additional information from other sensors (G4 and G40).
It is a little tricky to test because there are several pins on the connector, and each one has different functions. The best way to do it is by measuring the resistance between the ECU and the sensor. If the sensor is operational, it should be reading approximately 1000 ohms. If you're having issues with this sensor, look key for audi signs of coolant or oil in the connector bay.
2. Injectors
Yesterday accelerating full speed from highway paytoll i had an abrupt drop in power like the engine is out of gas or the injectors aren't firing anymore. Today, i pulled out the spark plugs, 3 were drenched in gazoline, the fourth one was dry. I placed a tissue over each hole in the injector and when i start the engine with no sparks, the three that have gazoline pop right out. The fourth one remains shut. I tested the ground connection of ECU pins 14,30 and 48/55. I got 0ohm. So i assume the problem is elsewhere.
I also tried to reset the PID without success. The car will start when the G28 is disconnected, but it runs fine with the G28 plugged in. However, the intermittent misfire problem persists at higher RPM. The coolant temperature sensor (G62) shows the wrong temperature of that is -49c even after unplugging it. I also noticed that the oil gauge in the cockpit shows 2 bar while the actual pressure is 0.
I don't know what to do. I feel like i've pretty much all other possibilities out. I'm concerned that i may have missed something. If anyone has any ideas please let me know! TIA!
3. Fuel Pump
The fuel pump on the g28 is activated by a signal sent by the RPM sensor. The GM-style transmitter is identical 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 simple to test them - put your DMM in resistance mode and measure between pins 1 (with the bump on the connector's end up) and 2 (2nd from left on the black end of the connector). They must be infinite ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY) engines needs to be aware of the speed and position of the crankshaft to determine timing of the fuel injector, etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these goes bad you will get codes on the diagnostic scanner which can lead to engine shutdown.
A damaged G28 sensor could result in an inaccurate gearbox speed counter, a gearbox that shifts more quickly than normal, and/or an unfire when in the gear. If you experience any of these issues it is likely that your sensor is failing and needs replacing. They're inexpensive and easy to locate, especially if they're an Bosch unit like ours. Alternatively, the GM version of this component is also a good choice.
5. Tachometer
A failing engine speed sensor could be the cause of a slew of problems in your vehicle. It's an essential component of the transmission in your audi car key replacement cost Keyless Go (http://daoqiao.net/), as it transmits information to the ECU on how fast or slow the engine is turning. This sensor can cause the transmission to fail and other components in the car to be affected.
The G5 engine speed sensor is located at the outside of the transmission above the flywheel ring gear. It transmits a signal to the ECU at pin T55/49 via an uncolored wire. The ECU utilizes this signal to regulate fuel and boost, as well as timig. It also transmits it to the G5 Tachometer inside the instrument cluster. You can check for sensor failure by examining the continuity of the sensor to the tachometer. You can also verify 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 observe around 1000 ohms of resistance between those two pins. This is a typical component across the audi replacement key service 80, 100 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU so good ones could be available in wrecking yards.