• 목록
• 답변
• 글쓰기
• 게시판 리스트 옵션
  • 수정
  • 삭제

How to Replace an replacement audi a4 key G28 Engine Speed Sensor

In this video Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. This sensor is located on the outside of the transmission over the flywheel 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

The grey wire is situated on the outside of the transmission, directly above the flywheel ring. The sensor sends a signal via the grey wire to pin T55/49. The ECU then uses this information to control fuel, timig and boost. It also sends an alert to the G5 Tachometer within the instrument cluster.

The sensor is used to link the G40 Camshaft position Sensor. The ecu must know when the crankshaft is TDC and where the camshaft is located so that it can trigger spark and injectors accordingly.

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 be a sign of a chain stretch or a jumpy chain link in the upper chain of timing. However, the code won't appear on its own, without additional information from other sensors (G4 and G40).

It is a little tricky to test since there are different connector pins, and each has its own functions. The best way to do it is by measuring the resistance between the ECU and the sensor. If the sensor is functional, it should read about 1000 ohms. If you are having problems with this sensor, look for evidence of coolant or oil in the connector bay.

2. Injectors

Yesterday, as i was accelerating off the highway paytoll at full speed, i noticed a huge decrease in power. It was as if the engine had run out of gas. Or, my injectors were not firing. Today, i pulled out the spark plugs, 3 were soaked with gazoline and the 4th one was dry. I placed a tissue over each hole in the injector and when i turn the engine on without sparks, the three with gazoline jump right out. The fourth one remains shut. I tried to test the ground connections of ECU pins 14,30 and 48/55. I got zero ohm. I'm assuming that the issue is elsewhere.

I also tried to reset PID but without success. The car can start if the G28 is disconnected and runs fine when it is plugged in however it has the intermittent misfire issue at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature value of -49c, even if I unplug it. I also noticed that the oil gauge in the cockpit shows 2 bars while the actual pressure is zero.

I'm not certain what to do, i think i've pretty much eliminated everything else. I'm worried that i might have missed something. Please let me know if you have any ideas! TIA!

3. Fuel Pump

The fuel pump in the g28 receives signals from the RPM sensor. The GM-style sender is identical to the G4 and both are used in the 80 100, 200, UrS and RS2 cars so you can easily find one at a salvage yard or in a local parts store. Test them out - put your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector end up) and 2 (2nd from left on the black connector's side). They must be infinite Ohms.

4. ECU

The ECU in our 20vt turbo (3B AAN ABY ADU) engines must know the speed and position of the crankshaft in order to make a decision about timing of fuel injectors, repaired etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these goes bad you will get codes on the diagnostic scanner that can lead to engine shutdown.

Some of the symptoms of a failing G28 sensor are an inaccurate rev counter in the gearbox, gears shifting quicker than normal and/or misfiring when you are in gear. It is likely that your sensor is failing and needs to be replaced if you experience any of these signs. The good news is they are very affordable and readily available particularly in the case of an Bosch model, which is what ours are. If you prefer, GM's version of this part would be a good option.

5. Tachometer

A faulty engine speed sensor could be the cause of a slew of problems in your car. It's an essential component of the audi a3 key fob replacement's transmission because it communicates to the ECU about how the car's crankshaft is spinning. This sensor can cause the transmission to malfunction and other components in the car to be affected.

The G5 engine sensor is located at the outskirts of the transmission, just above the flywheel ring. It sends an electrical signal through an uncolored wire to the ECU pin T55/49. The ECU then processes the signal to control fuel, timig, and boost, and also transmitting it to the G5 tachometer inside the instrument cluster. You can test for sensor failure by checking continuity from the sensor to the tachometer. Additionally, you can check 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 an average resistance of 1000 ohms between these points. This part is common across the audi a3 key fob replacement 80-100-200-RS2 model, ranging beginning with the 1985 MC and up to the 1997 UrS AN and 1995 RS2 Du You may also find good ones in wrecking yards.