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. The sensor is located at the edge of transmission, above the flywheel gear. It transmits a signal to the ECU via the grey wire T55/49 and then to the tachometer in the instrument cluster.
1. Engine Speed Sensor
The grey wire is located at the edges of the transmission, above the flywheel ring. This sensor sends a signal via the grey wire to pin T55/49. The ECU uses this information to regulate the amount of fuel 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 must know when the crankshaft is TDC and the location of the camshaft so it can activate spark and injectors according to the situation.
If this sensor fails the ECU will throw the P00160 error, which means the Crank Shaft and Intake Camshaft are out of sync, possibly indicating chain stretch or a jumped link on the upper chain of timing. The code will not appear without the additional information supplied by other sensors (G4 or G40).
It can be a bit difficult to test because there are different pins on the connector and each has its own functions. The most effective method to test it is to measure the resistance between the ECU and the sensor. It should read about 1000 ohms when the sensor is in full operation. 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 the injectors aren't firing any more. This morning i pull out the spark plugs, three were drenched with gazoline the 4th one was dry. I put a piece of tissue over each hole in the injector and when I start the engine without sparks, the 3 with gazoline jump right out. The fourth one remains closed. I checked the ground connection of ECU pins 14,30 and 48/55. I found 0ohm. Therefore, i think the issue is in another place.
I also tried to reset the PID but with no luck. The car will start when the G28 is disconnected, but it works fine when the G28 plugged in. However the intermittent misfire issue still occurs at higher RPM. The temperature sensor for coolant (G62) shows the wrong temp value -49c even when i unplug it. Also, i noticed that the gauge for oil pressure in the cockpit shows 2 bar when the actual pressure is 0.0 when i rev the engine.
just click the up coming internet page 'm not sure what to do. I feel like i've pretty much ruled everything else out. I'm concerned that i may have missed something. If anyone has suggestions, please share them! 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 junkyard or in a local parts store. Test them out by putting your DMM in resistance mode and take measurements between pins 1 (with the bump on the connector end up) and 2 (2nd from the left on the black connector's side). They must be infinite ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY) engines needs to be aware of the position and speed the crankshaft to make decisions regarding timing of 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, the diagnostic scanner will display codes that could cause the engine shutting down.
The signs of a malfunctioning G28 sensor are an inaccurate gearbox rev counter the gears are shifting faster than normal, and/or a misfire when you are in gear. If you have any of these problems, it is likely that your sensor is deteriorating and requires replacement. The good news is they are very affordable and easy to find, especially if you're looking at the Bosch sensor, like ours. If you prefer, GM's version of this component is an option.
5. Tachometer
A failing engine speed sensor could be a cause for a slew of problems in your car. It's an essential component of your Audi's transmission, because it communicates to the ECU about how the car's crankshaft is spinning. This sensor could cause the transmission to fail and other components of the car to be affected.
The G5 engine speed sensor is situated on the edge of the transmission, above the flywheel ring gear and sends a signal to the ECU at pin T55/49, via a grey wire. The ECU is then able to process this signal to control fuel, timig, and boost, and also transmitting it to the G5 Tachometer located in the instrument cluster. You can test the sensor for failure by checking continuity between it and the tachometer. You can also check continuity between ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. You should detect the resistance to be around 1000 ohms between these two points. This part is common across the Audi 80-100-200-RS2 series, starting from the 1985 MC all the way up to the 1997 UrS AN and the 1995 RS2 Du, so you might find some good ones in wrecking yards.