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

How to Replace an audi q5 key G28 Engine Speed Sensor

In this video Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. The sensor is located on the edge of the transmission above the flywheel ring gear. It transmits a signal to the ECU through a grey wire T55/49, then to the tachometer on the instrument cluster.

1. Engine Speed Sensor

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

The sensor serves as a reference for comparing with the G40 Camshaft Position Sensor. The ecu has to know when the crankshaft has reached TDC and also where the camshaft lies in order to activate the spark and injectors.

If this sensor fails, the ECU will throw a P00160 code which means the Crank Shaft and audi car key Holder Intake Camshaft are not in sync and possibly indicating the chain is stretched or a jump link on the upper chain of timing. However, the error code won't appear on its own without additional information from other sensors (G4 and G40).

Testing can be a bit difficult since there are two connector pins and they serve different purposes but the most effective way to test it is to measure the resistance between the sensor and the ECU. It should read about 1000 ohms when the sensor is in full operation. If you're having issues with this part, check for signs of coolant or oil in the connector bay.

2. Injectors

Yesterday, while accelerating at full speed from the highway paytoll i had a big cut in power as if the engine was running out of gas or the injectors are not firing at all. This morning i pull out the spark plugs. Three were drenched with gazoline the fourth was dry. I put tissue over each hole in the injector and when i start the engine without sparks, the 3 with gazoline jump out. The 4th one stays closed. I checked the ground connection of ECU pins 14,30 and 48/55. I got zero ohm. Therefore, i think the issue is elsewhere.

I also tried to reset the PID but with no luck. The car will start when the G28 is disconnected, but it is running fine with the G28 plugged in. However, the intermittent misfire problem continues to occur at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature value of -49c even when i unplug it. Also, i noticed that the oil pressure gauge in the cockpit is showing 2 bar while the actual pressure is 0.0 when I crank up the engine.

I don't know what to do. I think I've ruled everything else out. But i am afraid I may have missed something. If anyone has any ideas please chime in! TIA!

3. Fuel Pump

The fuel pump in the g28 can be activated by a signal sent by 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 wrecking yard or at a parts store. It is simple to test them - put your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector's end up) and 2 (2nd from left on the black connector's side). They must be infinite Ohms.

4. ECU

Our 20vt turbo (3B, AAN, ABY and ADU) engines have an ECU that needs to know the speed and position of the crankshaft to make a decision about timing of the fuel injectors, etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you encounter a problem with either one of these, the diagnostic scanner will display the codes that could trigger an engine shutdown.

Some of the signs of a failed G28 sensor are an inaccurate rev counter for the gearbox and gears that shift faster than normal and/or a misfire when in gear. If you have any of these problems, it is likely your sensor is deteriorating and requires Replacement audi A3 key. The good news is that they are very affordable and readily available, especially if you're looking at an Bosch unit which is what we have. Alternately, the GM version of this component is also a good option.

5. Tachometer

A failing engine speed sensor could be the cause of many problems in your vehicle. It's an essential component of the audi a5 key fob's transmission as it sends information to the ECU about how fast or slow the car's crankshaft is rotating. If the sensor fails, it could disrupt the performance of the transmission and the other car's components.

The G5 engine speed sensor is located at the outside of the transmission above the flywheel ring gear and transmits a signal to the ECU at pin T55/49, via an uncolored wire. The ECU is then able to process the signal to control fuel, timig and boost as well as transmitting it to the G5 Tachometer located in the instrument cluster. You can test for sensor failure by examining the continuity of the sensor to the tachometer. Also, you can examine the continuity between pins T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]) and between pin T6a/1 and pin T26a/12. You should detect the resistance to be around 1000 ohms between these two points. This is the same across the replacement audi key fob 80-100-200-RS2 range, beginning with the 1985 MC and up to the 1997 UrS An and 1995 RS2 Du, so you might find some good ones in wrecking yards.