How to Replace an audi replacement car keys G28 Engine Speed Sensor
In this video Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. The sensor is situated at the top of the transmission just above the flywheel ring 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
The grey wire is situated on the outside of the transmission, directly above the flywheel ring. The sensor sends signals through the grey wire to pin T55/49. The ECU uses this information to regulate fuel and boost. It also sends an indicator to the G5 Tachometer in instrument cluster.
The sensor is used to link with the G40 Camshaft position Sensor. The ecu must know when the crankshaft is TDC and Audi smart key replacement the location of the camshaft so it can trigger spark and injectors accordingly.
If this sensor fails, the ECU will display a P00160 error message. This means that the Crank Shaft is out of sync with the Intake Camshaft. It could also be a sign of a chain stretch or a jumpy chain link in the upper chain. However the code will not be displayed on its own without additional information from other sensors (G4 and G40).
It can be a bit difficult to test since there are various pins on the connector and they all have different functions. The best way to do it is by measuring the resistance between the ECU and the sensor. It should read about 1000 ohms when it is at full operation. If you’re having issues with this sensor, look key for audi signs of coolant or oil in the connector bay.
2. Injectors
Yesterday, when accelerating from highway paytoll at a high speed, i noticed a huge decrease in power. It was like the engine had run out of gas. Or, my injectors weren’t firing. I pulled out the spark plugs this morning, 3 were drenched in gasoline and the fourth was unclean. I placed a tissue over each hole in the injector and when i turn the engine on without sparks, the 3 with gazoline jump out. The 4th one remains closed. I tested the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ i get zero ohm. I assume that the problem is elsewhere.
I also tried to reset PID but without success. The car will start when the G28 is disconnected, but it works fine when the G28 connected. However, the intermittent misfire problem persists at higher RPM. The coolant sensor (G62), even if it is not plugged in, shows a temperature of -49c. I also noticed that the oil gauge in the cockpit shows 2 bar when the actual pressure is 0.
I’m not certain what to do, but i think i’ve pretty much eliminated everything else. I’m afraid i may have missed something. If anyone has suggestions, please chime in! 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 similar to the G4 sender and works on the 80,100,200, UrS, and RS2 vehicles. You can easily locate an extra in a wrecking shop or parts store. It is easy to test them – simply switch your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump on the connector’s edge facing upwards). They must be infinite Ohms.
4. ECU
Our 20vt turbo (3B AAN, repairer ABY, and ADU) engines are equipped with an ECU that must know the speed and position of the crankshaft to make decisions about timing of the fuel injectors, etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these go bad you will get codes on the diagnostic scanner that could cause engine shut down.
A damaged G28 sensor could cause an inaccurate speed counter for the gearbox, a gearbox that shifts more quickly than normal, and/or an unfire when in gear. It is possible that the sensor is failing and requires to be replaced if you experience any of these symptoms. They’re cheap and easy to find particularly when they’re a Bosch sensor like ours. If you prefer, GM’s version of this part would be an option.
5. Tachometer
A faulty engine speed sensor could be a cause for numerous issues in your vehicle. It is a crucial part of your Audi A5 Key Fob‘s transmission, as it sends information to the ECU about how fast or slow the vehicle’s crankshaft is turning. If this sensor fails, it will affect the performance of the transmission as well as the other car’s components.
The G5 engine sensor is located at the outskirts of the transmission, just above the flywheel ring. It sends a signal via a gray wire to the ECU pin T55/49. The ECU uses this signal to control the amount of fuel and boost, as well as timig. It also sends it to the G5 Tachometer inside the instrument cluster. You can check the sensor for failure by examining the continuity between it and the tachometer, between ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. You should observe around 1000 ohms of resistance between those points. This is a typical part that is found across the audi a1 car key 80, 100 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU, so the best ones might be availble in wrecking yards.
