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 near the edges of the transmission just above the flywheel ring gear. It transmits a signal to the ECU via an uncolored wire (T55/49) and then to the tachometer within the instrument cluster.
1. Engine Speed Sensor
It is located on the outside of the transmission just above the flywheel ring gear G28 Engine Speed Sensor sends an electrical signal to ECU pin T55/49 through the grey wire. The ECU then uses this information to control the flow of fuel, timig and boost. It also sends an alert to the G5 Tachometer located in the instrument cluster.
The sensor serves as a reference to correlate 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 trigger spark and injectors according to the situation.
If this sensor fails, the ECU will display the P00160 error, which means the Crank Shaft and Intake Camshaft are not in sync and possibly indicating chain stretch or a jumped link on the upper timing chain. However the code will not appear on its own, without additional information from other sensors (G4 and G40).
It is a little tricky to test since there are various pins on the connector, and they all have different functions. The best method for doing this is to measure the resistance between the ECU and the sensor. If the sensor is functional, it should read about 1000 ohms. Check for signs of coolant, or oil in the connector bay if there are issues with this part.
2. Injectors
Yesterday, as i was accelerating off the highway paytoll at maximum speed I noticed a massive decrease in power. It was as if the engine had run out of gas. Or, my injectors were not firing. I took out the spark plugs this morning and found that 3 were drenched in gasoline and the fourth was unclean. When I start the engine, there are no sparks, i place a tissue on the top of each hole in the injector and the 3 drenched with gazoline jump out but the 4th one stays shut. I tried to test the ground connections of ECU pins 14,30, and 48/55. I got 0ohm. I'm assuming that the issue is somewhere else.
I also tried to reset PID without success. The car can start if the G28 is disconnected and is running fine when it is connected however it has the intermittent misfire issue at higher RPM. audi replacement key uk for coolant (G62) shows the wrong temperature value of that is -49c even after unplugging it. I also noticed that the oil gauge in the cockpit shows 2 bars but the actual pressure is 0.
I'm not certain what to do, i feel i have pretty much completely ruled out all other possibilities. But i am afraid I might have missed something. If anyone has suggestions, please let me know! TIA!
3. Fuel Pump
The fuel pump in the g28 gets a signal from the RPM sensor. The GM-style sensor is identical to 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 junkyard or from 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 end up) and 2 (2nd from the left on the black connector's side). They should be infinite Ohms.
4. ECU
The ECU of our 20vt turbo (3B AAN ABY ADU) engines must know both the position and speed of the crankshaft to make decisions regarding timing of fuel injectors, etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these go wrong, you will receive codes on the diagnostic scanner which can lead to engine shutdown.
A damaged G28 sensor could cause an inaccurate speed counter for your gearbox or a gearbox that shifts more quickly than normal, or a misfire in gear. It is probable that the sensor is failing and needs to be replaced if you notice any of these signs. The good news is that they are very cheap and easily accessible particularly if you're looking at the Bosch sensor, like ours. Alternately, GM's version this part is a good option.
5. Tachometer
A failing engine sensor could cause a variety of issues in your vehicle. It is an important part of the transmission of your Audi because it relays information to the ECU about how fast or slowly the engine of the car is turning. When this sensor fails, it will cause problems for the transmission, as well as the rest of the car's components.
The G5 engine speed sensor is located on the outside of the transmission above the flywheel ring gear. It sends a signal directly to the ECU at pin T55/49, via a grey wire. The ECU uses this signal to control fuel and boost, and also to timigrate. It also sends it to the G5 Tachometer located in the instrument cluster. You can check for sensor failure by examining the continuity from the sensor to the tachometer. Also, you can verify continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]) and between pin T6a/1 as well as pin T26a/12. You should see approximately 1000 ohms resistance between those two pins. car key replacement audi is a standard component across the Audi 80 100, 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU, so the best parts could be found in wrecking yards.