14 Creative Ways To Spend On Leftover Audi G28 Budget
How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. The sensor is located near the edges of the transmission just above the flywheel ring gear. It sends a message to the ECU via an uncolored wire T55/49, then to the tachometer located on the instrument cluster.
1. Engine Speed Sensor
The grey wire is situated on the edge of transmission, above the flywheel ring. This sensor sends a signal via the grey wire to pin T55/49. The ECU uses this information to control the amount of fuel and boost. It also sends an alert to the G5 Tachometer in instrument cluster.
The sensor is used to correlate with the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft has reached TDC, and the position of the camshaft, so that it can activate the spark and injectors.
If this sensor fails, the ECU will display a P00160 code which means the Crank Shaft and Intake Camshaft aren't in sync, possibly indicating the chain stretching or a jump link on the upper chain of timing. However the code will not appear on its own without additional information from other sensors (G4 and G40).
Testing can be a bit difficult as there are two different pins for the connector and they serve different purposes but the most effective way to test it is to measure the resistance between the sensor and the ECU. If the sensor is operational, it should be reading about 1000 ohms. Check for signs of coolant, or oil in the connector bay if there are problems with this part.
2. Injectors
Yesterday, while accelerating at full speed from the highway paytoll i had an abrupt drop in power as if the engine was running out of gas or injectors are not firing any more. Today, i pulled out the spark plugs, 3 were drenched in gazoline, the fourth one was dry. When I crank the engine, there are no sparks i put tissue on top of each injector hole and 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 0ohm. So i assume the problem is in another place.
I also tried to reset the PID with no success. The car will start when the G28 is disconnected, but it works fine when the G28 plugged in. However, the intermittent misfire problem still occurs at higher RPM. The coolant sensor (G62) even when unplugged, still shows temperatures of -49c. I also noticed that the oil gauge in the cockpit shows 2 bars when the actual pressure is zero.
I'm not certain what to do, i think i've pretty much completely ruled out all other possibilities. I'm concerned that i may have missed something. Please let me know if you have any ideas! TIA!
3. Fuel Pump
The fuel pump in the g28 is activated by a signal by the RPM sensor. The GM-style transmitter functions similarly to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. You can easily find an extra in a wrecking shop or parts store. It is simple to test them: simply put your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump at the connector's end facing up). They must be infinite Ohms.
4. ECU
Our 20vt turbo (3B AAN, ABY and ADU) engines have an ECU that needs to know the position and speed of the crankshaft in order to make decisions about fuel injector timing etc. To do this, it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these goes badly, you will see codes on the diagnostic scanner which can cause the engine to shut down.
The signs of a failing G28 sensor are an inaccurate rev counter for the gearbox, gears shifting quicker than normal, and/or a misfire when you're in gear. If you are experiencing any of these issues, it is likely that your sensor is going bad and should be replaced. They're cheap and easy to find, especially in the case of a Bosch sensor like ours. You can also choose the GM version of this component is also a good choice.
5. Tachometer
A failing engine speed sensor could be the reason behind numerous issues in your car. It's an essential component of the transmission in your Audi because it relays information to the ECU regarding how fast or slowly the engine of the car is spinning. This sensor can cause the transmission to malfunction and other car components to be affected.
replacement audi key is located on the edge of the transmission above the flywheel ring gear. It transmits a signal to the ECU at pin T55/49 via a grey wire. The ECU is then able to process the signal to control fuel, timig and boost, and also transmitting it to the G5 tachometer inside the instrument cluster. You can check for sensor failure by examining the continuity of the sensor to the tachometer. You can also 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 see a resistance of approximately 1000 ohms between these points. This is a common part across the Audi 80 100 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU so good parts could be found in wrecking yards.