20 Trailblazers Are Leading The Way In Audi G28
20 Trailblazers Are Leading The Way In Audi G28
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How to Replace an Audi 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 top of the transmission above the flywheel ring gear. It sends a message to the ECU via a grey wire T55/49, then to the tachometer in the instrument cluster.
1. Engine Speed Sensor
The grey wire is located at the edges of the transmission, just above the flywheel ring. The sensor transmits signals through the grey wire to pin T55/49. The ECU uses this information to control the amount of fuel and boost. It also sends an indication to the G5 tachometer inside the instrument cluster.
The sensor is used as a reference point to connect with the G40 Camshaft Position Sensor. The ecu has to be aware of when the crankshaft has reached TDC and also the location of the camshaft so that it can activate the spark and injectors.
If this sensor fails when it fails, the ECU will display a P00160 error message. This means that the Crank Shaft is out of alignment with the Intake Camshaft. It could also be a sign of the possibility of a chain stretch or jumpy chain link in the upper timing chain. The code won't appear without the additional information supplied by other sensors (G4 or G40).
Testing is a bit challenging since there are two connector pins, and they serve different purposes but the most effective method to test it is to measure the resistance between the sensor and the ECU. If the sensor is functional, it should read approximately 1000 ohms. Examine for evidence of coolant or oil in the connector bay if there are issues with this component.
2. Injectors
Yesterday, as i was accelerating off the highway paytoll at maximum speed, i noticed a huge decrease in power. It was as if the engine had run out of gas. Or my injectors weren't firing. In the morning, i removed the spark plugs. Three were drenched with gazoline the fourth one was dry. When i crank the engine with no sparks i put tissue on top of each injector hole, the 3 drenched with gazoline jump out but the 4th stays closed. I tried to test the ground connections of ECU pins 14,30 and 48/55. I got zero ohm. I'm assuming the issue is somewhere else.
I also tried to reset PID but without success. The car will start if the G28 is not plugged in and is running fine when it is connected, but still is experiencing intermittent misfires at higher RPM. The coolant click here sensor (G62) even here when unplugged, still shows a temperature of -49c. Also i 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 certain what to do, i feel i have pretty much eliminated everything else. I'm worried that i might have missed something. Let me know should you have any suggestions! TIA!
3. Fuel Pump
The fuel pump in the g28 gets a signal from the RPM sensor. The GM-style sensor is the same as the G4 and both are used in the 80 100 200, UrS and RS2 cars which is why you can easily locate one at a salvage yard or at a parts store. It is simple to more info test them: simply put your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump at the connector end facing upwards). They must be infinite Ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY) engines needs to know both the position and speed of the crankshaft in order to make a decision about fuel injector timing, etc. To accomplish this, it utilizes a get more info 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 which could cause engine shut down.
The signs of a failed G28 sensor include an inaccurate rev counter for the gearbox, gears shifting quicker than normal and/or misfiring when in gear. If you experience any of these issues, it is likely that your sensor is deteriorating and needs replacing. They're inexpensive and easy to locate especially if they're a Bosch sensor like ours. You can also choose the GM version of this part is also a great option.
5. Tachometer
A damaged engine sensor could cause a number of problems in your vehicle. It's an essential component of the transmission in your Audi because it relays information to the ECU about how fast or slow the engine is turning. This sensor can cause the transmission to malfunction and other car components 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 is then able to process this signal to regulate the flow of fuel, timig and boost, and also sends it on to the G5 tachometer in the instrument cluster. You can test the sensor for failure by examining the continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection on pin T6a/1 (trace [79trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. It should show around 1000 ohms of resistance between those points. This is the same across the Audi 80-100-200-RS2 series, starting from the 1985 MC up to the 1997 UrS AN and the 1995 RS2 more info DU, so you might find them in wrecking yards.