Take A Look At The Steve Jobs Of The Audi G28 Industry
How to Replace an Audi G28 Engine Speed Sensor
In this video, Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. This sensor is situated on the outside of the transmission, above the flywheel gear. It transmits a signal 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 at the edges of the transmission, directly above the flywheel ring. The sensor transmits an electrical signal through the grey wire to pin T55/49. The ECU then uses this information to control fuel, timig and boost. It also sends an indication to the G5 Tachometer within the instrument cluster.
The sensor is used to correlate with the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft reached TDC, and the location of the camshaft so that it can activate the spark and injectors.
If this sensor fails to function, the ECU will display a P00160 error message. This indicates that the Crank Shaft is out of line with the Intake Camshaft. It could also be a sign of the possibility of a chain stretch or jumped chain link in the upper chain of timing. However the code will not be displayed on its own without additional information from other sensors (G4 and G40).
It is a little tricky to test because there are several pins on the connector and each has its own functions. The most effective method to test it is by measuring the resistance between the ECU and the sensor. It should read around 1000 ohms when it is at full operation. Check for evidence of coolant or oil in the connector bay if there are issues with this component.
2. Injectors
Yesterday accelerating full speed from highway paytoll i had massive power loss like the engine is running out of gas or the injectors aren't firing any more. Today, i pulled out the spark plugs, three were soaked with gazoline and the fourth was dry. When i crank the engine, there are no sparks, i place a tissue on the top of each of the injector holes and the 3 that were drenched in gazoline jump out but the 4th stay closed. I tried to test the ground connections of ECU pins 14,30, and 48/55. I got zero ohm. I'm assuming the issue is somewhere else.
I also tried to reset the PID with no success. The car will start when the G28 is disconnected, but it is running fine with the G28 plugged in. However the intermittent misfire issue continues to occur at higher RPM. The coolant temperature sensor (G62) shows the wrong temperature of -49c even when i unplug it. I also noticed that the oil gauge in the cockpit shows 2 bars while the actual pressure is zero.
I don't know what to do. I think I've ruled everything else out. I'm worried that i might have missed something. Please let me know If you have any suggestions! TIA!
3. Fuel Pump
The fuel pump on the g28 is activated by a signal by the RPM sensor. The GM-style transmitter is identical to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. It is easy to find a spare in a wrecking shop or a 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
The ECU in our 20vt turbo (3B AAN ABY) engines needs to know the speed and position of the crankshaft in order to make a decision about timing of fuel injectors, etc. It makes use of 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 the codes that could trigger an engine shut down.
A damaged G28 sensor can cause an inaccurate speed counter for your gearbox and a gearbox which shifts more quickly than normal, or an unfire when in gear. It is likely that your sensor is failing and requires to be replaced if you notice any of these signs. The good news is they are quite affordable and easy to find, especially in the case of the Bosch unit which is what ours are. Alternately, GM's version this part would be an option.
5. Tachometer
A malfunctioning engine speed sensor could be the reason behind numerous issues with your vehicle. It's an essential component of your Audi's transmission, as it sends information to the ECU about how fast or slow the vehicle's crankshaft is rotating. If the sensor fails, it can disrupt the performance of the transmission as well as the rest of the car's components.
The G5 engine speed sensor is situated on the outside of the transmission just above the flywheel ring gear and sends a signal directly to the ECU at pin T55/49 via an uncolored wire. The ECU uses this signal to control the amount of fuel and boost, and also to timigrate. replacement audi car key transmits it to the G5 Tachometer inside the instrument cluster. You can check the sensor for failure by examining the continuity between it and the tachometer, between ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. You should detect a resistance of approximately 1000 ohms between these points. This part is common across the Audi 80-100-200-RS2 range, from the 1985 MC up to the 1997 UrS An and 1995 RS2 Du So, you may find them in wrecking yards.