The No. One Question That Everyone Working In Audi G28 Needs To Know How To Answer
The No. One Question That Everyone Working In Audi G28 Needs To Know How To Answer
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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 on the outside of the transmission over the flywheel gear. It sends a message to the ECU through the grey wire T55/49 and then to the tachometer in the instrument cluster.
1. Engine Speed Sensor
The sensor is located at the edge of the transmission just above the flywheel ring gear G28 Engine Speed Sensor sends a signal to ECU pin T55/49 via the grey wire. The ECU then utilizes this information to regulate the flow of fuel, timig and boost. It also sends an indication to the G5 Tachometer located in the instrument cluster.
The sensor is used as a reference for comparing with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft is TDC and where the camshaft is located so that it can activate spark and injectors accordingly.
If this sensor fails, the ECU will show an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are out of sync and could indicate the chain is stretched or a jump link on the upper timing chain. However, the error code won't appear on its own, without additional information from other sensors (G4 and G40).
Testing can be a bit difficult as there are two different connector pins, and they perform different functions however the best method to test it is to measure resistance between the sensor and the ECU. It should read about 1000 ohms when the sensor is in full operation. If you are having problems with this component, look for signs of coolant or oil in the connector bay.
2. Injectors
Yesterday, as i was accelerating off the highway paytoll at a high speed, i noticed a huge reduction in power. It was as if the engine was running out of gas. Or, my injectors were not firing. This morning i pull out the spark plugs, three were drenched in gazoline, the fourth one was dry. When I start the engine without sparks, i place a tissue on the top of each hole in the injector and the 3 that were drenched in gazoline jump out but the 4th one stays closed. I tried to test the ground connections of ECU pins 14,30, and 48/55. I found 0ohm. I'm assuming the issue is somewhere else.
I also tried to reset the PID without success. The car will start when the G28 is disconnected, but it works fine when the G28 plugged in. However, the intermittent misfire new audi key problem continues to occur at higher RPM. The coolant temperature sensor (G62) shows the wrong temperature of that is -49c even after unplugging it. I also noticed that the oil gauge in the cockpit shows 2 bars when the actual pressure is zero.
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. Please let me know should you here have any suggestions! 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 operate on the 80,100,200, UrS, and RS2 vehicles. You can easily find an extra in a wrecking shop or a parts store. Test them out to do - just put your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector's side 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 ADU) engines needs to know both the position and speed the crankshaft to make decisions regarding fuel injector timing, etc. In order to do this it uses a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you encounter a problem with either of these sensors, the diagnostic scanner will display codes that could lead to an engine shut down.
A damaged G28 sensor could result in an inaccurate speed counter for the gearbox and a gearbox which shifts more quickly than normal, or a misfire while in the gear. If you are experiencing 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, especially in how much is a replacement audi key the case of an Bosch model, like ours. You can also choose the GM version of this unit is also a good choice.
5. Tachometer
A faulty engine speed sensor could be the reason behind a slew of issues with your car. It's a vital component of the Audi's transmission as it sends information to the ECU about how the car's crankshaft is spinning. When this sensor fails, it can cause problems for the transmission and the other car's components.
The G5 engine sensor is located at the outskirts of the transmission, just above the flywheel ring. It sends an electrical signal through a gray wire to the ECU pin T55/49. The ECU uses this signal to control the amount of fuel and boost, as well as timig. It also relays it to the G5 Tachometer in instrument cluster. You can test for sensor failure by examining the continuity of the sensor to the tachometer. Additionally, you can verify continuity between pin T55/49 of the ECU check here and pin T6a/1 of the instrument cluster (trace [79trace [79]), and between pin T6a/1 as well here as pin T26a/12. You should see an average resistance of 1000 ohms between these points. This part is common across the Audi 80-100-200-RS2 series, starting 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.