How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician shows you how to replace the G28 Engine Speed Sensor. The sensor is located on the edge of the transmission, above the flywheel ring gear. It transmits a signal the ECU via an uncolored wire (T55/49), then to the tachometer located in the instrument cluster.
1. Engine Speed Sensor
It is located on the outside of the transmission, above the flywheel ring gear the G28 Engine Speed Sensor sends signals to ECU pin T55/49 through a grey wire. The ECU then uses this information to control fuel, timig and boost. It also sends signals to the G5 tachometer in the instrument cluster.
The sensor is used to link with the G40 Camshaft position Sensor. The ecu has to know when the crankshaft reached TDC and also the location of the camshaft so that it can activate the spark and injectors.
If this sensor fails to function, the ECU will display an error code P00160. This indicates that the Crank Shaft is out of alignment with the Intake Camshaft. It could also indicate an issue with the chain or a jump in the chain link of the upper chain of timing. However, the error code won't appear on its own without additional information from other sensors (G4 and G40).
It's a bit tricky to test because there are different pins on the connector, and they all have different functions. The most effective method to test it is to measure the resistance between the ECU and the sensor. When the sensor is operational, it should be reading around 1000 ohms. Look for signs of coolant or oil in the connector bay if there are issues with this component.
2. Injectors
Yesterday, while accelerating at full speed from the highway paytoll i had a big cut in power as if the engine was running out of gas or injectors are not firing anymore. I took out the spark plugs this morning and found that 3 were soaked in gasoline, and the 4th was dry. I put tissue over each injector hole and when i start the engine with no sparks, the 3 that have gazoline pop right out. The 4th one stays shut. I inspected the ground connection on ECU pins 14/55, 30/55 and 48/55. I get 0ohm. I assume that the problem is in another location.
I also tried to reset the PID but without success. The car can start when the G28 is not plugged in and is running fine when it is connected however it is experiencing intermittent misfires at higher RPM. The coolant temperature sensor (G62) shows the wrong temp value -49c, even if I unplug it. I also noticed that the gauge for oil pressure in the cockpit is showing 2 bar while the actual pressure is 0.0 when I crank up the engine.
I'm not certain what to do, as i think i've pretty much completely ruled out all other possibilities. However, i'm afraid that I may have missed something. If anyone has suggestions, please share them! TIA!
3. Fuel Pump
The fuel pump in the g28 is activated by a signal by the RPM sensor. The GM-style transmitter is identical to the G4 and they both work in the 80 100 200, UrS and RS2 cars so you can easily find one at a junkyard or at a parts store. It is simple to test them to do - just put your DMM in resistance mode and measure between pins 1 (with the bump on the connector's end up) and 2 (2nd from the left on the black end of the connector). They must be infinite Ohms.
4. ECU
The ECU of our 20vt turbo (3B AAN ABY ADU) engines must be aware of the position and speed the crankshaft in order to make a decision about timing of fuel injectors, etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If either of these sensors go bad you will get codes on the diagnostic scanner that could cause engine shut down.
A damaged G28 sensor
Audi Key Shell could result in an inaccurate speed counter for the gearbox, a gearbox that shifts faster than normal, and/or a misfire in gear. If you experience any of these issues, it is likely that your sensor is deteriorating and requires
replacement audi key cost uk. They're inexpensive and easy to locate especially when they're a Bosch unit like ours. Alternatively, the GM version of this part is also a good choice.
5. Tachometer
A malfunctioning engine sensor can cause a myriad of issues in your vehicle. It's a crucial component of the transmission of your
spare audi key because it relays information to the ECU on how fast or slow the engine of the car is spinning. If this sensor fails, it will disrupt the performance of the transmission, as well as the rest of the car's components.
The G5 engine sensor is located near the edge of the transmission, over the flywheel ring. It transmits signals via a gray wire to the ECU pin T55/49. The ECU then processes the signal to control the flow of fuel, timig and boost, and also sends it on to the G5 Tachometer located in the instrument cluster. You can determine if the sensor is in failure by examining the continuity of the sensor to the tachometer. Also, you can examine the continuity between pins T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]) and between pin T6a/1 and pin T26a/12. You should detect a resistance of approximately 1000 ohms in these areas. This is a common part that is found across the
Audi key Shell 80, 100 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU so good parts could be found in wrecking yards.
