How to Replace an Audi G28 Engine Speed Sensor
In this video, Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. This sensor is located near the transmission's edge just above the flywheel gear. It transmits a signal to the ECU via a grey wire T55/49, then to the tachometer on the instrument cluster.
1. Engine Speed Sensor
Located on the edge of the transmission above the flywheel ring gear the G28 Engine Speed Sensor sends a signal to ECU pin T55/49 via the grey wire. The ECU uses this information to control fuel and boost. It also sends an indicator to the G5 Tachometer located in the instrument cluster.
The sensor is used to correlate with the G40 Camshaft position Sensor. The ecu must know when the crankshaft has reached TDC and also the position of the camshaft, to trigger the spark and injectors.
If this sensor fails the ECU will show the P00160 error, which means the Crank Shaft and Intake Camshaft are out of sync and could indicate the chain stretching or a jump link on the upper timing chain. The code won't appear without the additional information provided by other sensors (G4 or G40).
It can be a bit difficult to test since there are various connector pins, and they all have different functions. The best method for doing this is by measuring the resistance between the ECU and the sensor. When the sensor is operational, it should read about 1000 ohms. Check for evidence of coolant or oil in the connector bay if there are issues with this part.
2. Injectors
Yesterday accelerating full speed from highway paytoll, i experienced massive power loss like the engine is out of gas or injectors aren't firing at all. I pulled out the spark plugs this morning and found that 3 were drenched in gasoline and the fourth was dry. I put a piece of tissue over each injector hole, and when I turn the engine on without sparks, the 3 with gazoline jump right out. The 4th one stays closed. I checked the ground connection on ECU pins 14/55,30/55 and 48/55 i get 0ohm. I'm assuming that the issue is in another location.
I also tried to reset the PID without success. The car will start when click here the G28 is unplugged, and it runs fine with the G28 plugged in. However the intermittent misfire issue continues to occur at higher RPM. The coolant sensor (G62) even if it is not plugged in, shows a temperature of -49c. I also noticed that the gauge for oil pressure in the cockpit shows audi key programming near me 2 bar while the actual pressure is 0.0 when i rev the engine.
I'm not sure what to do, as i think i've pretty much ruled out everything else. But i am afraid i might have audi a1 key replacement missed something. Let me know if you have any ideas! TIA!
3. Fuel Pump
The fuel pump in the g28 can be activated by a signal by the RPM sensor. The GM-style transmitter functions similarly to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. You can easily locate a website spare in a wrecking shop or a parts store. Testing them is easy by putting your DMM in resistance mode and measure between pins 1 (with the bump on the connector end up) and 2 (2nd from left on the black connector's end). They should be infinite ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY ADU) engines requires to be aware of the position and speed of the crankshaft to make decisions regarding timing of the fuel injector, etc. 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 malfunctioning G28 sensor could result in an inaccurate speed counter for the gearbox or a gearbox that shifts more quickly than normal, and/or an unfire when in the gear. It is probable that the sensor is failing and requires to be replaced if you encounter any of these signs. The good news is that they are quite affordable and readily available, especially if you're looking at a Bosch sensor, which is what click here we have. You can also choose the GM version of this unit is also a great option.
5. Tachometer
A faulty engine speed sensor could be a cause for numerous problems in your vehicle. It is a crucial part of your Audi's transmission, as it sends information to the ECU about how fast or slow the car's crankshaft is spinning. If this sensor fails, it can cause problems for the transmission as well as the rest of the car's components.
The G5 engine speed sensor is located at the outside of the transmission, above the flywheel ring gear and sends a signal to the ECU at pin T55/49 through a grey wire. The ECU then processes this signal to regulate fuel, timig and boost, and also sends it on to the G5 tachometer in the instrument cluster. You can check the sensor for failure by checking continuity between it and the tachometer. You can also check continuity between ECU pin T55/49 and the instrument cluster connection on pin T6a/1 (trace [79trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. You should see approximately 1000 ohms of resistance between those points. This is a typical component across the Audi 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.