How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician teaches you how to replace the G28 Engine Speed Sensor. This sensor is located on the edge of the transmission, above the flywheel ring gear. It sends a signal to the ECU via a grey wire (T55/49) and then to the tachometer located in the instrument cluster.
1. Engine Speed Sensor
It is located on the outside of the transmission, above the flywheel ring gear the G28 Engine Speed Sensor sends an electrical signal to ECU pin T55/49 using an uncolored wire. The ECU utilizes this information to control the amount of fuel and boost. It also sends signals to the G5 Tachometer located in the instrument cluster.
The sensor is used as a reference point to connect with the G40 Camshaft Position Sensor. The ecu needs to be aware of when the crankshaft has reached TDC and also where the camshaft lies in order to activate the spark and injectors.
If this sensor fails when it fails, the ECU will display a P00160 error message. This indicates that the Crank Shaft is not in sync with the Intake Camshaft. It could also indicate an issue with the chain or a jumped chain link in the upper chain of timing. The code will not appear without the additional information supplied by other sensors (G4 or G40).
It is a little tricky to test since there are various connector pins, and each has its own functions. The best way to do it is to measure the resistance between the ECU and the sensor. It should read approximately 1000 ohms if the sensor is operating at its maximum. If you're having issues with this sensor, look for signs of coolant or oil in the connector bay.
2. Injectors
Yesterday, while accelerating from the highway paytoll at full speed I noticed a massive reduction in power. It was as if the engine was running out of gas. Or, my injectors were not firing. I took out the spark plugs this morning and found that 3 were drenched in gasoline and the fourth was dry. When i crank the engine with no sparks i put tissue on the top of each of the injector holes and the 3 drenched with gazoline pop out, but the 4th stay shut. I checked the ground connection of ECU pins 14,30, and 48/55. I found 0ohm. I think the issue is in another location.
I also tried to reset PID but without success. The car will start when the G28 is unplugged, and it is running fine with the G28 connected. However the intermittent misfire issue continues to occur at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temp value -49c, even if I unplug it. Also i noticed that the oil pressure gauge in the cockpit is showing 2 bar when the actual pressure is 0.0 when i rev the engine.
I'm not sure what to do. I believe that I've ruled everything else out. I'm afraid i may 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 sender is the same as the G4 and they both work in the 80, 100, 200, UrS and RS2 cars so you can easily find one at a salvage yard or from a parts store. It is simple to test them - simply switch your DMM into resistance mode and test the distance between pins 1 and 2 (with the bump on the connector's edge facing up). They should be infinite Ohms.
4. Visit Homepage in our 20vt turbo (3B AAN ABY ADU) engines must know the speed and position of the crankshaft in order to make a decision about fuel injector timing, etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you encounter a problem with either of these, the diagnostic scanner will display codes that could lead to the engine shutting down.
The signs of a malfunctioning G28 sensor are an inaccurate rev counter in the gearbox, gears shifting quicker than normal and/or a misfire when you are in gear. If you are experiencing any of these problems, it is likely your sensor is going bad and needs replacing. The good news is that they are very affordable and easily accessible particularly in the case of the Bosch unit which is what we have. Alternatively, GM's version of this part would be a good option.
5. Tachometer
A malfunctioning engine speed sensor could be a cause for a slew of issues with your car. It's an essential component of the Audi's transmission as it sends information to the ECU about how fast or slow the vehicle's crankshaft is turning. This sensor can cause the transmission to malfunction and other car components to be affected.
The G5 engine speed sensor is situated on the outside of the transmission above the flywheel ring gear and sends a signal directly to the ECU at pin T55/49, via an uncolored wire. The ECU is then able to process the signal to control 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. You can also check continuity between 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. click through the next document should detect the resistance to be around 1000 ohms between these two points. This is a standard part 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 good ones could be available in wrecking yards.