How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician teaches how to replace the G28 Engine Speed Sensor. This sensor is located at the top of the transmission, above the flywheel ring gear. It sends a message to the ECU via the grey wire T55/49 and then to the tachometer in the instrument cluster.
1. Engine Speed Sensor
The grey wire is situated on the edge of transmission, above the flywheel ring. This sensor sends signals through the grey wire to pin T55/49. The ECU then utilizes this information to regulate the boost, fuel, and timig. It also sends an indication to the G5 tachometer inside the instrument cluster.
The sensor is used to connect the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft is TDC and the location of the camshaft so it can trigger spark and injectors accordingly.
If this sensor fails to function, the ECU will display a P00160 error message. This indicates that the Crank Shaft is out of alignment with the Intake Camshaft. It could also indicate a chain stretch or a jump in the chain link of the upper chain. However the code will not be displayed on its own without additional information from other sensors (G4 and G40).
It is a little tricky to test as there are different connector pins, and each has its own functions. The most effective method to test it is by measuring the resistance between the ECU and the sensor. It should read about 1000 ohms when the sensor is in full operation. If you're having issues with this component, look for evidence of coolant or oil in the connector bay.
2. Injectors
Yesterday accelerating full speed from highway paytoll, i experienced a big cut in power like the engine is running out of gas or injectors aren't firing anymore. I took out the spark plugs this morning, 3 were soaked in gasoline, and the fourth was unclean. When i crank the engine without sparks i put tissue on top of each injector hole, the 3 drenched with gazoline jump out but the 4th stays closed. I inspected the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ i get 0ohm. Therefore, i think the issue is in another place.
I also tried to reset the PID with no success. The car is able to start if the G28 is disconnected and is running fine when it is plugged in but it still has the intermittent misfire issue at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature value of -49c, even if I unplug it. Also i noticed that the gauge for oil pressure in the audi key replacement near me cockpit shows 2 bar while the actual pressure is 0.0 when I crank up the engine.
I'm not sure what to do, as i think i've pretty much eliminated everything else. I'm worried that i might have missed something. If anyone has suggestions, please share them! TIA!
3. Fuel Pump
The fuel pump of the g28 gets a signal from the RPM sensor. The GM-style transmitter is identical to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. It is easy to find the spare in a salvage shop or parts store. It is simple to test them: simply put your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump at audi lost key the connector end facing up). They must be infinite Ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY ADU) engines needs to be aware of the speed and position of the crankshaft to make decisions regarding get more info timing of the fuel injector, etc. To accomplish this, it uses a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these sensors go bad you will get codes on the diagnostic scanner that can cause the engine to shut down.
A damaged G28 sensor could result in an inaccurate speed counter for the gearbox and a gearbox which shifts more quickly than normal, or an unfire website when in gear. If you experience any of these issues it is likely your sensor is going bad and should be replaced. They're inexpensive and easy to locate particularly when they're a Bosch model like ours. Alternately, GM's version this part would be an excellent choice.
5. Tachometer
A failing engine speed sensor could website be a cause for a slew of problems in your vehicle. It's a crucial component of the transmission in your Audi because it relays information to the ECU about how fast or slow the engine of the car is spinning. This sensor can cause the transmission to fail and other components in the car to be affected.
The G5 engine speed sensor is situated on the outside of the transmission just above the flywheel ring gear and transmits a signal to the ECU at pin T55/49 through an uncolored wire. The ECU uses this signal to regulate fuel and boost, as well as timig. It also relays it to the G5 Tachometer in instrument cluster. You can check for sensor failure by examining the continuity of 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 of resistance between these two points. This is a common feature across the Audi 80-100-200-RS2 series, starting from the 1985 MC up to the 1997 UrS AN and the 1995 RS2 DU So, you may find them in wrecking yards.