20 Trailblazers Setting The Standard In Audi G28 > 자유게시판

How to Replace an Audi Q7 Replacement Key G28 Engine Speed Sensor

In this video Charles the Humble Mechanic demonstrates how to replace the G28 engine speed sensor. This sensor is located at the edge of transmission just above the flywheel gear. It transmits a signal to the ECU via the grey wire (T55/49) which is then sent to the tachometer within the instrument cluster.

1. Engine Speed Sensor

The grey wire is located at the edges 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 the amount of fuel and boost. It also sends signals to the G5 tachometer inside the instrument cluster.

The sensor is used to correlate 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 in the right way.

If this sensor fails when it fails, the ECU will display a P00160 error code. 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 jumped chain link in the upper timing chain. However, the code won't appear on its own, without additional information from other sensors (G4 and G40).

Testing is a bit tricky because there are two connector pins and they serve different purposes however the best method of testing it is to measure resistance between the sensor and the ECU. When the sensor is functional, it should read approximately 1000 ohms. Check for signs of coolant, or oil in the connector bay if you have issues with this component.

2. Injectors

Yesterday, while accelerating from the highway paytoll at full speed I noticed a significant drop in power. It was as if the engine had run out of gas. Or my injectors were not firing. This morning i pull out the spark plugs, audi Q7 replacement key three were drenched with gazoline the fourth one was dry. I put tissue over each injector hole and when I turn the engine on without sparks, the three with gazoline jump right out. The 4th one stays shut. I tested the ground connection of ECU pins 14,30 and 48/55. I found 0ohm. I think the issue is somewhere else.

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 continues to occur at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temp value -49c even when i unplug it. I also noticed that the oil pressure gauge in the cockpit is showing 2 bar, whereas 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 eliminated everything else. However, i'm afraid that i might have missed something. Let me know should you have any suggestions! TIA!

3. Fuel Pump

The fuel pump in the g28 receives a signal from the RPM sensor. The GM-style sensor is the same as the G4 and they both work in the 80, 100, 200, UrS and RS2 cars so you can easily find one at a salvage yard or from a parts store. It is simple to test them - simply switch your DMM into resistance mode and test the distance between pins 1 and 2 (with the bump at the connector's end facing upwards). They must be infinite Ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY and ADU) engines have an ECU that must be aware of the speed and position of the crankshaft in order to make a decision about timing of the fuel injectors, etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you have a problem with either of these sensors, the diagnostic scanner will show codes that could lead to an engine shutdown.

Some of the signs of a malfunctioning G28 sensor are an inaccurate rev counter in the gearbox, gears shifting quicker than normal and/or misfiring when you are in gear. If you have any of these issues it is most likely that your sensor is going bad and requires replacement. The good news is that they are very affordable and easy to find particularly if you're looking at the Bosch sensor, like ours. Alternatively, the GM version of this unit is also a great option.

5. Tachometer

A damaged engine sensor could cause a variety of issues in your vehicle. It's a crucial component of the transmission of your Audi, as it transmits information to the ECU about how fast or slow the car's engine is turning. This sensor can cause the transmission to malfunction and other components of the car to be affected.

The G5 engine speed sensor is located at the edge of the transmission, above the flywheel ring gear. It sends a signal to the ECU at pin T55/49 via an uncolored wire. The ECU utilizes this signal to control fuel and boost, and also to timigrate. It also relays it to the G5 Tachometer located in the instrument cluster. You can test for sensor failure by examining the continuity from the sensor to the tachometer. Additionally, you can verify continuity between pin 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 observe approximately 1000 ohms resistance between those points. This is the same across the audi new key 80-100-200-RS2 range, beginning with the 1985 MC and up to the 1997 UrS An and 1995 RS2 DU You may also find some good ones in wrecking yards.