The 10 Worst Audi G28-Related FAILS Of All Time Could Have Been Avoided
The 10 Worst Audi G28-Related FAILS Of All Time Could Have Been Avoided
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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. The sensor is located near the edges of the transmission, 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, directly above the flywheel ring. This sensor sends signals through the grey wire to pin T55/49. The ECU then uses this information to control the boost, fuel, and timig. It also sends an indication to the G5 tachometer inside the instrument cluster.
The sensor is used as a reference to correlate with the G40 Camshaft Position Sensor. The ecu needs to be aware of when the crankshaft has reached TDC and also the location of the camshaft to trigger the spark and injectors.
If this sensor fails, the ECU will display an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are not in sync, possibly indicating the chain is stretched or a jump link on the upper chain of timing. The code won't show without the additional information provided by other sensors (G4 or G40).
Testing is a bit tricky since there are two pins for the connector and they have different functions but the best method to test it is by measuring resistance between the sensor and the ECU. When the sensor is fully functional, it should read approximately 1000 ohms. If you are having problems with this component, look for evidence of oil or coolant in the connector bay.
2. Injectors
Yesterday, when accelerating from highway paytoll at full speed I noticed a massive reduction in power. It was like the engine was running out of gas. Or, my injectors weren't firing. I pulled out the spark plugs this morning and found that 3 were drenched in gasoline and the 4th was dry. I put tissue over each hole in the injector and when I turn the engine on without sparks, the three with gazoline jump right out. The fourth one remains shut. I inspected the ground connection on ECU pins 14/55,30/55 and 48/55 I get 0ohm. I think the issue is elsewhere.
I also tried to reset the PID but without 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 more info occurs at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature value of -49c, even if 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 don't know what to do. I think I've eliminated everything else. I'm afraid i may have missed something. Please let more info me know if you have any ideas! TIA!
3. Fuel Pump
The fuel pump in the g28 can be activated by a signal by the RPM sensor. The GM-style sender is the same as 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 at a parts store. It is easy to test them: simply put your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump at the connector end facing up). They must be infinite Ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY ADU) engines must be aware of the position and speed of the crankshaft to determine fuel injector timing, etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If you encounter a problem with either one of these, the diagnostic scanner will show the codes that could trigger an engine shut down.
A damaged G28 sensor could result in an inaccurate gearbox speed counter and a gearbox which shifts more quickly than normal, and/or a misfire while in the gear. It is likely that the sensor is failing and needs to be replaced if you encounter any of these symptoms. The good news is they are very affordable and easily accessible particularly when you're looking at a Bosch sensor, which is what ours are. Alternatively, GM's version of this part would be an option.
5. Tachometer
A malfunctioning engine speed sensor could be the reason behind numerous problems in your car. It's an essential component of the Audi's transmission since it relays information to the ECU about how fast or slow the vehicle's crankshaft is rotating. This sensor can cause the transmission to malfunction and other components in the car to be affected.
The G5 engine speed sensor is located at the outside of the transmission above the flywheel ring gear. It transmits a signal to the ECU at pin T55/49 via an uncolored wire. click here The ECU utilizes this signal to control the flow of fuel and boost as well as timig. It also transmits it to the G5 Tachometer in instrument cluster. You can test for sensor failure by checking continuity from the sensor to the tachometer. You can also verify continuity between pin T55/49 of the click here ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]) and between pin T6a/1 and pin T26a/12. You should detect an average resistance of 1000 ohms in these areas. This is a common part website that is found across the Audi 80 100 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU, so the best ones could be available in wrecking yards.